Repeaters for wireless communication systems

• US 20040110469A1
• Filed: 09/10/2003
• Published: 06/10/2004
• Est. Priority Date: 01/14/2000
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Lovinggood, Breck W., Veihl, Jonathon C., Tennant, David T., Judd, Mano D., Maca, Gregory A., Kuiper, William P., Alford, James L., Thomas, Michael D.
• Granted Patent: US 7,577,398 B2
• Time in Patent Office: Days
• US Class Current: 455/15
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: H01Q 1/007 specially adapted for indoor communication
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 25/005 providing two patterns of opposite direction; back to back antennas H01Q25/004 takes precedence
• CPC Class Codes: H01Q 3/2611 Means for null steering; Adaptive interference nulling
• CPC Class Codes: H01Q 3/2647 Retrodirective arrays
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays
• CPC Class Codes: H04B 7/0825 with main and with auxiliary or diversity antennas
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/15507 Relay station based processing for cell extension or control of coverage area, network planning with network coordinated processing with regard to cell extension H04W16/26; network topologies using dedicated repeater stations H04W84/047; terminal devices adapted for relaying to or from an other terminal H04W88/04
• CPC Class Codes: H04B 7/1555 Selecting relay station antenna mode, e.g. selecting omnidirectional -, directional beams, selecting polarizations
• CPC Class Codes: H04B 7/15564 Relay station antennae loop interference reduction
• CPC Class Codes: H04B 7/15585 by interference cancellation

Abstract

A flat-panel repeater includes a housing having a pair of oppositely facing surfaces, at least one antenna element mounted to each of the surfaces for radiating energy in a direction opposite to that of an antenna element mounted to the other of the surfaces, and an electronic circuit mounted within the housing and operatively coupling signals between at least one antenna element on each of the oppositely facing surfaces of the module. Isolation between the antennas on opposite sides of the repeater is improved by various techniques, such as use of adaptive cancellation which removes a significant portion of the feedback signal power, therefore increasing the total system isolation by the same amount. This additional isolation can be used to achieve greater system gain, and therefore significantly extend the range of the system. The repeater may also include a beamforming arrangement for creating a desired antenna pattern of one antenna relative to a base station and a desired antenna pattern of the other antenna relative to subscriber equipment.

Claims

1. A signal repeater comprising:

a housing having generally oppositely facing surfaces;

at least one antenna positioned on each of said surfaces for radiating energy in generally opposite directions;

electronic circuitry positioned in the housing and operatively coupling signals between the antennas.

2. The repeater of claim 1 wherein a thickness dimension of the housing is in the range of two to six inches and the greater of a height and width dimension is in the range of one to two feet.

3. The repeater of claim 1 wherein the antennas are planar.

4. The repeater of claim 1 wherein said electronic circuitry includes a planar PC board supporting repeater electronics.

5. The repeater of claim 1 wherein said antennas each comprise radiating elements printed on a planar substrate supported adjacent a ground plane.

6. The repeater of claim 1 said antennas include microstrip patches.

7. The repeater of claim 1 wherein at least one of said antennas radiates with a first polarization, and an antenna on an oppositely facing surface radiates with a second polarization orthogonal to said first polarization.

8. The repeater of claim 1 wherein one of said antennas has a plurality of radiating elements.

9. The repeater of claim 5 wherein the planar substrate of at least one antenna is supported in a conforming recess in an associated ground plane.

10. The repeater of claim 1 wherein said housing includes an RF choke structure.

11. The repeater of claim 10 wherein said RF choke structure comprises at least one of an array of axially directed fins, and an array of outwardly directed fins.

12. The repeater of claim 11 wherein said fins have at least one of height and spacing dimensions related to one fourth wavelength of a center frequency of a band of frequencies to be radiated by said repeater.

13. The repeater of claim 8 wherein said antenna elements are spaced by one half wavelength of the center frequency of the frequency band to be radiated by the repeater.

14. A modular repeater comprising:

a housing having generally oppositely facing surfaces;

at least one antenna positioned on each of said surfaces for radiating energy in generally opposite directions;

the housing including an RF choke structure.

15. The repeater of claim 14 wherein said housing supports RF energy absorbing material.

16. The repeater of claim 14 wherein said RF choke structure comprises a series of fins.

17. The repeater of claim 16 wherein an outermost of said fins has the greatest height, and successively inward fins have progressively decreasing height.

18. The repeater of claim 16 wherein said RF choke comprises a series of concentric fins having a height and spacing related to one fourth wavelength of the center frequency in a band of frequencies to be radiated by said repeater.

19. The repeater of claim 18 wherein an outermost of said fins has the greatest height, and inner fins have progressively decreasing height.

20. A modular repeater comprising:

a housing having generally oppositely facing surfaces;

at least one antenna positioned on each of said surfaces for radiating energy in generally opposite directions;

electronic circuitry positioned in the housing and operatively coupling signals between the antennas, the electronic circuitry including feedback suppression structures for improving side-to-side isolation.

21. The repeater of claim 20 wherein said antennas each comprise radiating antenna elements located centrally of an associated ground plane of sufficient area to contribute significant feedback suppression.

22. The repeater of claim 20 wherein said electronic circuitry includes a digital adaptive cancellation system.

23. The repeater of claim 20 wherein said electronic circuitry includes an automatic gain control circuit.

24. A modular signal repeater comprising:

a housing having generally oppositely facing surfaces;

at least one antenna positioned on each of said surfaces for radiating energy in generally opposite directions;

at least one of said antennas having a ground plane and one or more radiating elements grouped in a central area of said ground plane, the area of said ground plane being significantly greater than the area of said central area.

25. The repeater of claim 24 wherein one of said antennas produces a beam that has a narrower half power beam width than the beam produced by the other of said antennas.

26. The repeater of claim 25 wherein the beam width of said one antenna is about 30 degrees, plus or minus 5 degrees and wherein the beam width of said other antenna is about 60 degrees, plus or minus 10 degrees.

27. The repeater of claim 24 wherein the ratio of ground plane area to central area is in the range of about 2 to 5.

28. The repeater of claim 24 wherein at least one of said antennas is operable to produce a null in the array factor on the horizons to reduce the direct coupling between said antennas.

29. The repeater of claim 24, said housing being sized and configured for a selected frequency band having a predetermined center frequency with wavelength “

X”

, the height, width and thickness dimensions of the housing being such that feedback energy at wavelength X travels a feedback path around the housing of predetermined length effective to improve side-to-side isolation.

30. The repeater of claim 29 wherein said housing has a circular outer configuration such that all feedback paths are of equal length.

31. The repeater of claim 30 wherein said wherein said housing has a rectangular outer configuration and said dimensions are such that the length of said feedback path has a compromise length.

32. A modular repeater comprising:

a unitary structure having oppositely facing antennas and electrically intervening amplification electronics which introduce a phase shift in amplified signals, said repeater being adapted for use with a selected frequency band having a center frequency with wavelength “

X”

;

the height, width and thickness dimensions of the repeater being such that as feedback energy at wavelength X travels along a feedback path around the repeater from one of said antennas to the other of said antennas a predetermined phase shift is introduced;

said predetermined phase shift, when combined with said amplification electronics phase shift and other known feedback phase shifts, being effective to improve the side-to-side isolation and gain performance of said repeater.

33. The repeater of claim 32 including an RF choke structure in the feedback path between said antennas, and wherein said other known feedback phase shifts includes a phase shift introduced by said RF choke structure.

34. A repeater comprising:

at least one antenna element for communicating in one direction and at least one antenna element for communicating in another direction;

a radio frequency uplink path and a radio frequency downlink path coupled between said antennas; and

an adaptive cancellation circuit in at least one of said radio frequency uplink path and said radio frequency downlink path and operable to generate a cancellation signal, which, when added to a radio frequency signal in the respective uplink and downlink paths, substantially reduces feedback signals present in said radio frequency signal.

35. The repeater of claim 34 wherein said adaptive cancellation circuit comprises:

a digital signal processor circuit which receives an incoming radio frequency signal from one of said radio frequency uplink and downlink paths and digitally samples and processes said incoming radio frequency signal to generate an intermediate frequency signal; and

a modulator circuit which receives said intermediate frequency signal and a sample of a radio frequency output signal from said one of said radio frequency uplink and downlink paths and generates said cancellation signal.

36. The repeater of claim 35 wherein said digital signal processor comprises a radio frequency downconverter which converts said incoming radio frequency signal to a lower frequency signal for digital sampling, an analog-to-digital converter coupled to the radio frequency downconverter, which digitizes said lower frequency signal, and a processor coupled to the analog-to-digital converter which computes a desired intermediate frequency signal for the modulator.

37. The repeater of claim 35 wherein said adaptive cancellation circuit further includes a summing junction which receives and sums said intermediate frequency signal and said incoming radio frequency signal.

38. The repeater of claim 37 wherein said digital signal processor circuit receives an output of said summing junction.

39. The repeater of claim 36 wherein said modulator circuit comprises a controllable attenuator which receives and attenuates the radio frequency output signal and an I/Q modulator coupled to said attenuator and to said processor.

40. The repeater of claim 34 wherein said repeater comprises:

a housing having a pair of substantially 180°

oppositely facing surfaces;

at least one antenna element mounted to each of said surfaces for radiating energy in a direction opposite to that of the antenna element mounted to the other of said surfaces; and

an electronic circuit mounted to said housing and operatively coupling signals between at least one antenna element on each of said pair of oppositely facing surfaces of said module.

41. The repeater of claim 40 wherein a single antenna element is mounted to each of said oppositely facing surfaces of said housing and wherein said electronic circuit includes a frequency diplexer operatively coupled with each of said antennas and a pair of signal transmission circuits coupled between said frequency diplexers.

42. The repeater of claim 40 wherein two antenna elements are mounted to each of side of said module housing, one for transmitting communications signals and one for receiving communications signals.

43. A repeater comprising:

a housing having generally opposing sides;

a first antenna mounted adjacent to one of the generally opposing sides of said housing;

a second antenna mounted adjacent to the other of said generally opposing sides of said housing;

repeater electronics mounted in said housing and operatively interconnecting said antennas; and

a beamforming arrangement coupled with at least one of the antennas for creating a desired antenna pattern for the antenna.

44. The repeater of claim 43 wherein said repeater electronics further include a downlink channel module and an uplink channel module operatively coupled between said antennas.

45. The repeater of claim 44 wherein the at least one antenna comprises an antenna array having a plurality of antenna elements and wherein said beamforming arrangement includes a Butler matrix operatively coupled with the antenna array.

46. The repeater of claim 43 wherein the at least one antenna includes separate transmit and receive antenna arrays.

47. The repeater of claim 43 wherein the at least one antenna comprises an antenna array comprising a plurality of one of patch antenna elements and dipole elements.

48. The repeater of claim 47 wherein the antenna comprises patch antenna elements comprising a reduced surface wave element.

49. The repeater of claim 43 wherein said antennas each comprise an antenna array having a plurality of antenna elements and wherein said beamforming arrangement includes a plurality of stripline feeds of varying lengths coupled with said antenna elements and a switching circuit for selecting one or more of said striplines to achieve a desired stripline delay.

50. The repeater of claim 43 wherein said repeater electronics further include an interference cancellation circuit for substantially reducing radio frequency interference feedback signals between said antennas in both an uplink path and a downlink path.

51. The repeater of claim 45 further including a memory for storing angle and elevation information for use in operating said Butler matrix.

52. The repeater of claim 43 wherein said antennas each comprise an antenna array having a plurality of antenna elements and wherein said beamforming arrangement includes a plurality of phase shifting elements respectively coupled with the antenna elements and each of said antenna arrays, and a controller for controlling operation of said phase shifting elements.

53. The repeater of claim 43 wherein said antennas are mounted on a printed circuit board.

54. The repeater of claim 45 wherein the array of antenna elements and said Butler matrix are mounted on a printed circuit board.

55. The repeater of claim 43 wherein the beamforming arrangement is operable for forming a plurality of beams with the antenna, and further comprising a switch operably coupled for selecting from the plurality of beams.

56. The repeater of claim 55 wherein the beamforming arrangement and switch are mounted on a printed circuit board.

57. The repeater of claim 55 further comprising a control circuit for controlling the operation of the switch.

58. The repeater of claim 57 wherein the control circuit includes one of a modem and a transceiver.

59. The repeater of claim 56 wherein said antennas are mounted on said printed circuit board.

60. The repeater of claim 43 wherein at least one of the antennas comprises a array of transmission elements and an array of receive elements, the beamforming arrangement comprising beamforming circuitry for both of the arrays of the antenna for forming a plurality of transmit and receive beams with the antenna.

61. The repeater of claim 60 further comprising a switch operably coupled to each of the arrays for selecting from the plurality of beams from the arrays.

62. The repeater of claim 43 wherein the at least one antenna comprises an antenna array having a plurality of columns, each column including a plurality of antenna elements.

63. The repeater of claim 43 wherein one of said antennas is a dipole and the respective housing opposing side is reflective.

64. The repeater of claim 63 wherein said reflective side is shaped.

65. The repeater of claim 43 wherein one of said generally opposing sides is angled with respect to the other of the generally opposing sides.

66. A repeater comprising:

a housing having generally opposing sides;

an antenna mounted adjacent to one of the generally opposing sides of said housing;

multiple antennas mounted adjacent to the other of said generally opposing sides of said housing;

repeater electronics mounted in said housing and operatively interconnecting said antennas.

67. A repeater comprising:

a housing having generally opposing sides;

a first antenna mounted on the housing to extend upwardly from and adjacent to one of the generally opposing sides of said housing;

a second antenna mounted on the housing adjacent to the other of said generally opposing sides of said housing;

repeater electronics mounted in said housing and operatively interconnecting said antennas.

68. The repeater of claim 67 wherein said first antenna is one of a monopole and a dipole.

69. The repeater of claim 67 wherein said first antenna is vertically polarized.

70. The repeater of claim 67 wherein said second antenna is a generally planar antenna.

71. The repeater of claim 67 wherein said second antenna is horizontally polarized.

72. A repeater comprising:

a housing having generally opposing sides;

a first antenna mounted closely adjacent to one of the generally opposing sides of said housing;

a second antenna mounted closely adjacent to the other of said generally opposing sides of said housing;

repeater electronics mounted in said housing and operatively interconnecting said antennas; and

said repeater electronics including an interference cancellation circuit for effectively reducing interference feedback signals between said antennas in both an uplink path and a downlink path.

73. An integrated repeater comprising:

a housing having generally opposing sides;

a first antenna mounted on one of the generally opposing sides of said housing;

a second antenna mounted on the other of said generally opposing sides of said housing;

repeater electronics mounted in said housing and operatively interconnecting said antennas;

wherein said antennas each comprise a relatively flat antenna face having one or more antenna elements mounted thereon and a quantity of radio frequency absorbent material on each said antenna face.

74. The repeater of claim 73 further comprising a plurality of radio frequency chokes surrounding an antenna face.

75. The repeater of claim 74 wherein the quantity of radio frequency absorbent material is positioned between said chokes.

76. A method of repeating a radio frequency signal comprising:

receiving said radio frequency signal at one of a first antenna array mounted on one of generally opposing sides of a housing and a second antenna array mounted on the other of said generally opposing sides of said housing;

routing said signal, through repeater electronics mounted in said housing, to the other of the antenna arrays;

transmitting said signal from the other of said antenna arrays; and

beamforming for a desired antenna pattern of said first antenna array and a desired antenna pattern of said second antenna array.

77. The method of claim 76 further including substantially reducing radio frequency interference feedback signals between said antenna arrays in both an uplink path and a downlink path.

78. The method of claim 76 further including storing angle and elevation information for use in said beamforming.

79. The method of claim 76 wherein said beamforming includes phase shifting signals associated with antenna elements in the first antenna array and in the second antenna array and coupling the phase shifted signals to a radio frequency output.

80. The method of claim 76 wherein said beamforming comprises selecting the lengths of a plurality of striplines coupled respectively with the antennas elements of the first antenna array and second antenna array for variable stripline delay.

81. A method of repeating a radio frequency signal comprising:

receiving said radio frequency signal at one of a first antenna mounted on one of generally opposing sides of a housing and a second antenna mounted on the other of said generally opposing sides of said housing;

routing said signal, through repeater electronics mounted in said housing, to the other of the antenna arrays;

transmitting said radio frequency signal from the other of said antennas; and

substantially reducing interference feedback signals between said antennas in both an uplink path and a downlink path.

82. The method of claim 81 further including beamforming for creating a desired antenna pattern of said first antenna and a desired antenna pattern of said second antenna.

83. The method of claim 81 wherein said step of substantially reducing interference feedback signals comprises generating a cancellation signal, which when added to a radio frequency signal substantially reduces any feedback signal present in said radio frequency signal.

84. The method of claim 83 wherein said generating comprises digitally sampling and processing an incoming radio frequency signal having a feedback signal component to generate an intermediate frequency signal, and processing said intermediate frequency signal and a sample of a radio frequency output signal to generate said cancellation signal.

85. The method of claim 84 wherein said processing comprises converting said incoming radio frequency signal to a lower frequency signal for digital sampling, digitizing said lower frequency signal, and computing a desired intermediate frequency signal.

86. The method of claim 84 wherein said processing comprises controllably attenuating the radio frequency output signal sample and I/Q modulating the attenuated signal sample.

87. A repeater diversity antenna system comprising:

a main null antenna having a phase center and polarization for receiving a communications signal from a signal source;

a donor antenna for transmitting a signal to a station;

a diversity null antenna having a similiar phase center as the main null antenna and a polarization orthogonal to the polarization of the main null antenna;

a combining network coupled to the main null antenna and the diversity null antenna for combining the signals therefrom; and

an uplink channel module coupled with said combining network for delivering diversity combined receive signals to said donor antenna.

88. The antenna system of claim 87 wherein said combining network is operable to combine a signal from the main null antenna and the diversity null antenna with a fixed phase adjustment.

89. The system of claim 87 further including a low noise amplifier coupled intermediate said main null antenna and said combining network and having a predetermined gain, and a second low noise amplifier coupled intermediate said diversity null antenna and said combining network and having the same gain as the first low noise amplifier, such that the signals from the main null antenna and the diversity null antenna are combined at the combining network with equal gain.

90. The system of claim 87 and further including separate transmit and receive main null antenna elements.

91. An antenna system comprising:

a support structure including at least one substantially planar surface;

a plurality of antenna elements mounted to said planar surface of said support structure;

a Butler matrix mounted to said support structure, said Butler matrix having a plurality of inputs coupled respectively with said antenna elements and a plurality of outputs; and

a radio frequency switching circuit mounted to said support structure and operatively coupled with said outputs of said Butler matrix and having a control port responsive to a control signal for causing said switching circuit to select said outputs of said Butler matrix.

92. The antenna system of claim 91 wherein said support structure includes at least one printed circuit board.

93. The antenna system of claim 91 wherein said support structure further includes one or more printed circuit boards, said antenna elements, said Butler matrix and said radio frequency switch being mounted to one or more of said printed circuit boards.

94. The antenna system of claim 91 wherein said plurality of antenna elements are mounted in a horizontal array.

95. The antenna system of claim 91 wherein said plurality of antenna elements comprise a plurality of vertical columns of antenna elements, said columns being arranged side by side in a horizontal array, and each said column being summed at one input of said Butler matrix.

96. The antenna system of claim 91 wherein said plurality of antenna elements comprises a plurality of transmit antenna elements and a plurality of receive antenna elements and wherein said Butler matrix and said switching circuit are operatively coupled with said plurality of transmit antenna elements and further including a second Butler matrix having a plurality of inputs coupled with said receive antenna elements and a plurality of outputs, and a second radio frequency switching circuit coupled to the outputs of said second Butler matrix and having a control port responsive to a control signal for causing said switching circuit to select the outputs of said second Butler matrix.

97. The antenna system of claim 91 further including a radio frequency transceiver mounted to said support structure and operatively coupled with said radio frequency switch for sending radio frequency signals to, and receiving radio frequency signals from, the outputs of said Butler matrix.

98. The antenna system of claim 97 and further including a modem mounted to said support structure and operatively coupled with said radio frequency transceiver, said modem developing said control signal for said control port of said radio frequency switching circuit.

99. A method of operating an antenna system comprising:

receiving and transmitting radio frequency signals at a plurality of antenna elements mounted to a planar surface in a housing;

coupling the antenna elements to at least one Butler matrix mounted in the housing;

said Butler matrix transforming the receive response of said plurality of antenna elements into a corresponding plurality of narrow beams; and

selecting one of said narrow beams from said Butler matrix.

100. The method of claim 99 further including transforming, at said Butler matrix, a plurality of narrow beam transmit signal responses to a wider angle spatial transmit signal;

and wherein the step of selecting, includes selecting one of said narrow beams from said Butler matrix to be changed to a wider angle spatial transmit signal.

101. The method of claim 99 and further including sending radio frequency signals to, and receiving radio frequency signals from, the one of said outputs of said Butler matrix selected, using a radio frequency transceiver.

102. A method of re-transmitting a GPS signal inside a structure, the method comprising:

receiving the GPS signal;

amplifying the GPS signal to produce a second GPS signal; and

re-transmitting the second GPS signal inside the structure.

103. The method of claim 102, wherein the amplifying of the GPS signal includes down converting the GPS signal to an intermediate frequency (IF) signal, amplifying the IF signal, and up converting the IF signal to produce a radio frequency (RF) signal.

104. The method of claim 103, wherein the RF signal is the second GPS signal.

105. The method of claim 103, wherein the RF signal is an unlicensed frequency signal.

106. The method of claim 105, further including:

re-transmitting the unlicensed frequency signal inside the structure;

receiving the unlicensed frequency signal;

down converting the unlicensed frequency signal to a second IF signal;

amplifying the second IF signal;

up converting the second IF signal to produce the second GPS signal.

107. The method of claim 103, further including filtering the IF signal.

108. The method of claim 102, wherein the receiving is performed by a primary repeater.

109. The method of claim 108, wherein the primary repeater is coupled to an internal antenna for re-transmission.

110. The method of claim 103 further comprising:

re-transmitting the RF signal to a link antenna inside the structure;

receiving the RF signal;

down converting the RF signal to a second IF signal;

amplifying the second IF signal;

up converting the second IF signal to a second GPS signal; and

re-transmitting the second GPS signal inside the structure.

111. A GPS repeater for re-transmitting a GPS signal inside a structure, the repeater comprising:

a link antenna for receiving the GPS signal;

circiutry for amplifying the GPS signal to produce a second GPS signal; and

a broadcast antenna for re-transmitting the second GPS signal inside the structure.

112. The repeater of claim 111, wherein the circuitry is operable to down convert the GPS signal to an intermediate frequency (IF) signal, amplify the IF signal, and up convert the IF signal to produce a radio frequency (RF) signal.

113. The repeater of claim 112, wherein the RF signal is the second GPS signal.

114. The repeater of claim 112, wherein the RF signal is an unlicensed frequency signal.

115. The repeater of claim 114, further including a broadcast antenna for re-transmitting the unlicensed frequency signal inside the structure, and comprising a secondary repeater for receiving the unlicensed frequency signal, down converting the unlicensed frequency signal to a second IF signal, amplifying the second IF signal, and up converting the second IF signal to produce the second GPS signal.

116. The repeater of claim 111, wherein the circuitry includes a down converter for down converting the GPS signal to an intermediate frequency (IF) signal, a first amplifier for amplifying the IF signal, a filter for filtering the IF signal, a second amplifier for amplifying the IF signal and an up converter for up converting the IF signal to produce the second GPS signal.

117. The repeater of claim 111, wherein the circuitry includes a filter for filtering the GPS signal.

118. The system of claim 114, wherein the unlicensed frequency signal is about 2.4 GHz.

119. The system of claim 114, wherein the unlicensed frequency signal is about 902-928 MHz.

120. The system of claim 111, wherein the GPS signal is about 1.5 GHz.

121. A GPS repeater system for re-transmitting a GPS signal inside a structure, the repeater system comprising:

a primary repeater having a link antenna for receiving the GPS signal, a down converter for down converting the GPS signal to an intermediate frequency (IF) signal, an amplifier for amplifying the IF signal, an up converter for up converting the IF signal to a radio frequency (RF) signal, and a broadcast antenna for re-transmitting the RF signal inside the structure.

122. The system of claim 121, wherein the RF signal is a GPS signal.

123. The system of claim 121, wherein the RF signal is an unlicensed frequency signal.

124. The system of claim 123, further including a secondary repeater having a second link antenna for receiving the unlicensed frequency signal, a second down converter for down converting the unlicensed frequency signal to a second IF signal, a second amplifier for amplifying the second IF signal, a second up converter for up converting the second IF signal to a second GPS signal, and a second broadcast antenna for re-transmitting the second GPS signal inside the structure.

125. A method of re-transmitting a satellite signal inside a structure, the method comprising:

receiving the satellite signal;

amplifying the satellite signal to produce a second satellite signal; and

re-transmitting the second satellite signal inside the structure.

126. The method of claim 125, wherein the amplifying of the satellite signal includes down converting the satellite signal to an intermediate frequency (IF) signal, amplifying and filtering the IF signal, and up converting the IF signal to produce a radio frequency (RF) signal.

127. The method of claim 126, wherein the RF signal is the second satellite signal.

128. The method of claim 126, wherein the RF signal is an unlicensed frequency signal.

129. The method of claim 128, further including:

re-transmitting the unlicensed frequency signal inside the structure;

receiving the unlicensed frequency signal;

down converting the unlicensed frequency signal to a second IF signal;

amplifying the second IF signal;

up converting the second IF signal to produce the second satellite signal.

130. The method of claim 125 wherein the satellite signal is a digital radio signal.

131. A repeater for re-transmitting a satellite signal inside a structure, the repeater comprising:

a link antenna for receiving the satellite signal;

circuitry for amplifying the satellite signal and producing a second satellite signal; and

a broadcast antenna for re-transmitting the second satellite signal inside the structure.

132. The repeater of claim 131, wherein the circuitry down converts the satellite signal to an intermediate frequency (IF) signal, amplifies the IF signal, and up converts the IF signal to produce a radio frequency (RF) signal.

133. The repeater of claim 132, wherein the RF signal is the second satellite signal.

134. The repeater of claim 132, wherein the RF signal is an unlicensed frequency signal.

135. The repeater of claim 134, further including a broadcast antenna for re-transmitting the unlicensed frequency signal inside the structure, and a secondary repeater for receiving the unlicensed frequency signal, down converting the unlicensed frequency signal to a second IF signal, amplifying the second IF signal, and up converting the second IF signal to produce the second satellite signal.