Methods and Apparatuses for Adaptively Controlling Antenna Parameters to Enhance Efficiency and Maintain Antenna Size Compactness

• US 20060281423A1
• Filed: 06/02/2006
• Published: 12/14/2006
• Est. Priority Date: 10/15/2004
• Status: Active Grant

• Current Assignee: SkyCross Co., Ltd.
• Original Assignee: SkyCross, Inc.
• Inventors: Caimi, Frank M., O'Neill, Gregory A. Jr., Jo, Young-Min
• Granted Patent: US 7,834,813 B2
• Time in Patent Office: Days
• US Class Current: 455/129
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 9/045 with particular feeding means for circular polarisation H01Q9/0428

Abstract

An antenna for a communications device having configurable elements controlled to modify an antenna impedance and/or an antenna resonant frequency to improve performance of the communications device. The antenna impedance is controlled to substantially match to an output impedance of a power amplifier that supplies the antenna with a signal for transmission. The antenna resonant frequency is controlled to overcome the effects of various operating conditions that can detune the antenna or in response to an operable frequency band.

Claims

1. A communications apparatus comprising:

an antenna;

a power amplifier for operating on an input signal to supply a first signal to the antenna for transmitting, the antenna presenting a load impedance for the power amplifier, the first signal having a power-related parameter; and

a controller for controlling the load impedance according to the power-related parameter.

2. The communications apparatus of claim 1 wherein the controller is responsive to an operating parameter of the communications apparatus, the operating parameter representative of the power-related parameter.

3. The communications apparatus of claim 1 wherein controlling the load impedance responsive to the output power improves an efficiency of the power amplifier or a power added efficiency of the power amplifier.

4. The communications apparatus of claim 1 comprising a communications apparatus bidirectionally communicative with a remote station, the remote station commanding the communications apparatus to cause the power amplifier to supply the first signal having a desired power parameter, the controller controlling the load impedance according to the desired power-related parameter.

5. The communications apparatus of claim 1 wherein controlling the load impedance according to the power-related parameter improves a power amplifier efficiency, the controller for controlling the load impedance to yield a power amplifier efficiency between a first efficiency value and a second efficiency value, wherein when the power amplifier efficiency is the first efficiency value the controller controls the load impedance to change the power amplifier efficiency to the second efficiency value,

6. The communications apparatus of claim 1 wherein the antenna comprises selectable ground terminals, and wherein the controller causes one of the ground terminals to be connected to ground to control the load impedance.

7. The communications apparatus of claim 1 wherein the antenna comprises selectable feed terminals, and wherein the controller causes one of the feed terminal to receive the first signal to control the load impedance.

8. The communications apparatus of claim 1 wherein the controller controls the load impedance by controlling lumped reactive components or distributed reactive components operative with the antenna.

9. The communications device of claim 8 wherein the lumped reactive components or the distributed reactive components are connected in series with the antenna or in parallel with the antenna and ground.

10. The communications device of claim 1 wherein the power-related parameter comprises a power amplifier output power, an operating frequency of the communications device or a voltage standing wave ratio on a conductive path between the power amplifier and the antenna.

11. The communications apparatus of claim 1 wherein the controller is further responsive to manual control by a user of the communications apparatus.

12. The communications apparatus of claim 1 wherein the antenna comprises one of a planar inverted F antenna, a patch antenna, a dipole antenna, a monopole antenna disposed over a ground plane, a helical antenna, a spiral antenna and a dielectric resonant antenna.

13. The communications apparatus of claim 1 wherein the antenna comprises a plurality of selectable ground terminals and a plurality of selectable feed terminals, and wherein the controller selects an operative feed terminal from among the plurality of feed terminals to control the load impedance or selects an operative ground terminal from among the plurality of ground terminals to control the load impedance, and wherein the controller controls selectably operative switches to select the operative ground terminal or to select the operative feed terminal.

14. The communications device of claim 1 wherein the controller controls the load impedance to achieve a desired VSWR.

15. The communications apparatus of claim 1 wherein the controller further controls an effective antenna electrical length to control an antenna resonant frequency.

16. The communications apparatus of claim 1 further comprising reactive components cooperating with the antenna, the controller further for controlling a resonant frequency of the antenna responsive to an operating frequency of the apparatus, wherein the controller controls the reactive components to control the resonant frequency.

17. The communications apparatus of claim 1 wherein the power-related parameter comprises a peak DC current.

18. A communications apparatus comprising:

an antenna;

a power amplifier for operating on an input signal to supply a first signal to the antenna for transmitting, a power-related parameter associated with the first signal;

an controllable impedance element presenting a load impedance to the power amplifier; and

a controller for controlling the impedance element according to the power-related parameter.

19. An antenna for transmitting and receiving signals in spaced-apart frequency bands, the antenna comprising:

controllable antenna components control of which permits the antenna to present a resonant frequency in each one of the frequency bands and a first bandwidth including the resonant frequency, the first bandwidth sufficient to permit the antenna to receive or transmit a signal including information conveyed by the received or the transmitted signal; and

the antenna having a volume smaller than another antenna presenting a continuous second bandwidth including all of the frequency bands.

20. A communications apparatus comprising:

an antenna for transmitting signals, the antenna having a resonant frequency;

a power amplifier supplying a first signal to the antenna for transmitting, the antenna presenting a load impedance to the power amplifier, the power amplifier operating at an output power level; and

a controller for controlling the load impedance responsive to the output power level and for controlling the resonant frequency to a desired resonant frequency.

21. The communications apparatus of claim 20 wherein the controller controls the load impedance responsive to the power level to improve an efficiency of the power amplifier.

22. The communications apparatus of claim 20 operative with a remote transceiver for commanding the communications apparatus to an output power level and a resonant frequency.

23. The communications apparatus of claim 20 wherein the controller controls the resonant frequency by changing an effective electrical length of a resonant structure of the antenna.

24. The communications apparatus of claim 20 wherein the antenna comprises a meanderline element, the controller controlling the meanderline element to control a resonant frequency of the antenna.

25. The communications apparatus of claim 20 wherein the controller first controls the resonant frequency to a desired resonant frequency then controls the load impedance responsive to the output power level.

26. The communications apparatus of claim 20 wherein the controller is responsive to a signal representing a frequency of a signal transmitted by the communications device for controlling the resonant frequency to the desired resonant frequency.

27. The communications apparatus of claim 20 wherein the frequency of the signal transmitted by the communications device is affected by objects proximate the antenna.

28. The communications apparatus of claim 20 wherein the controller is responsive to a control signal representing a signal protocol of the first signal.

29. A communications apparatus comprising:

a multiband antenna selectively resonant in one of a plurality of frequency bands;

one or more controllable reactance elements operative with the antenna, the one or more reactance elements controllable to modify a resonant frequency of the antenna; and

a controller for controlling the one or more reactive elements to achieve antenna resonance in a desired one of the plurality of frequency bands.

30. The communications device of claim 29 wherein one of the one or more reactive elements comprises a varactor diode for producing a desired capacitive reactance.

31. The communications device of claim 29 wherein the antenna comprises a plurality of radiating segments with a parasitic capacitance between radiating segments, the one or more reactive elements controllable to modify the parasitic capacitances.

32. The communications apparatus of claim 29 operative with a remote transmitting station for assigning an operating frequency to the communications apparatus, wherein the controller is responsive to the assigned operating frequency for controlling the one or more reactive elements to achieve antenna resonance at the assigned operating frequency.

33. The communications apparatus of claim 29 capable of receiving and transmitting signals according to any one of a plurality of signal protocols, the controller responsive to a currently operable signal protocol for controlling the one or more reactive elements to achieve antenna resonance according to the currently operable signal protocol.

34. A communications apparatus capable of transmitting and receiving signals in a plurality of frequency bands comprising:

an antenna having multiple resonant frequencies;

a power amplifier for operating on an input signal to supply a first signal to the antenna for transmitting, a power-related parameter associated with the first signal;

a controllable impedance element presenting a load impedance to the power amplifier; and

a controller for controlling the impedance element according to the power-related parameter and for establishing an antenna resonant frequency from among the multiple resonant frequencies.

35. The communications apparatus of claim 34 responsive to a control signal indicating the power-related parameter or the antenna resonant frequency, wherein the controller is responsive to the control signal.

36. The communications apparatus of claim 34 wherein the controller controls an antenna effective electrical length, an inductance or a capacitance to establish the antenna resonant frequency.

37. A communications apparatus comprising:

an antenna for transmitting signals;

a power amplifier supplying a first signal to the antenna for transmitting, the antenna presenting a load impedance to the power amplifier, the power amplifier operating at an output power;

a filter interposed between the power amplifier and the antenna; and

a controller for controlling at least one of the antenna and the filter to control the load impedance presented to the power amplifier responsive to the power amplifier output power.

38. The communications apparatus of claim 37 further comprising a power sensor for determining the power amplifier output power and supplying a signal representative thereof to the controller.

39. The communications device of claim 37 wherein the controller comprises a first switching element for controlling operating characteristics of the antenna and a second switching element for controlling operating characteristics of the filter.

40. A communications apparatus comprising:

an antenna for selectively transmitting signals in a first frequency band and in a second frequency band;

a first power amplifier for selectively supplying a first signal in a first frequency band to the antenna for transmitting;

a second power amplifier for selectively supplying a second signal in a second frequency band to the antenna for transmitting;

a controller for controlling an operating frequency band of the antenna; and

a switching element operative to a first state for connecting the first power amplifier to the antenna responsive to operation of the communications apparatus in the first frequency band responsive to which the controller controls the antenna to a first resonant frequency in the first frequency band; and

the switching element operative to a second state for connecting the second power amplifier to the antenna responsive to operation of the communications apparatus in the second frequency band responsive to which the controller controls the antenna to second resonant frequency in the second frequency band.

41. The apparatus of claim 40 wherein the controller controls an antenna impedance responsive to an output power of the first or the second power amplifier.

42. An communications apparatus comprising:

a radiating structure;

a power amplifier;

a meanderline connected between the radiating structure and the power amplifier, the meanderline comprising a plurality of segments; and

an antenna controller for controlling an effective length of the meanderline responsive to a power output of the power amplifier.

43. The communications device of claim 42 wherein the antenna controller causes at least one segment of the meanderline to be connected to ground to control the effective length of the meanderline or causes at least one segment of the meanderline to be connected to an antenna feed to control the effective length of the meanderline.

44. The communications device of claim 42 wherein the antenna controller causes meanderline segments to be shorted to control the effective length of the meanderline.

45. A communications apparatus comprising:

a first and a second radiating structure;

a first and a second power amplifier;

a first, a second, a third and a fourth receiving amplifier;

a first and a second impedance controlling circuit connected to the first radiating structure;

a third and a fourth impedance controlling circuit connected to the second radiating structure;

a first switching element selectively connecting the first impedance controlling circuit to the first power amplifier in a first state and selectively connecting the first impedance controlling element to the first receiving amplifier in a second state;

a second switching element selectively connecting the second impedance controlling circuit to the first power amplifier in a first state and selectively connecting the first impedance controlling element to the second receiving amplifier in a second state;

a third switching element selectively connecting the third impedance controlling circuit to the second power amplifier in a first state and selectively connecting the third impedance controlling element to the third receiving amplifier in a second state; and

a fourth switching element selectively connecting the fourth impedance controlling circuit to the second power amplifier in a first state and selectively connecting the fourth impedance controlling element to the fourth receiving amplifier in a second state.

46. The communications device of claim 45 further comprising:

a first, a second, a third, a fourth, a fifth and a sixth filter connected to a respective input terminal of the first power amplifier, the second power amplifier, the first receiving amplifier, the second receiving amplifier, the third receiving amplifier and the fourth receiving amplifier.

47. The communications device of clam 45 wherein the first radiating structure presents a lower resonant frequency than the second radiating structure.

48. An antenna comprising:

a dielectric substrate;

a first and a second radiating structure disposed on different surfaces of the substrate;

an electronics module comprising;

a power amplifier;

a first controllable impedance element connected to the first radiating structure;

a second controllable impedance element connected to the second radiating structure; and

a controller for connecting the first controllable impedance element to the power amplifier in a first state and for connecting the second controllable impedance element to the power amplifier in a second state.

49. The antenna of claim 48 wherein the electronics module comprises an integrated circuit disposed in an interior region of the dielectric substrate.

50. An antenna comprising:

a dielectric substrate;

a first and a second radiating structure disposed on different surfaces of the substrate;

an electronics module comprising;

a first and a second power amplifier;

a first, a second, a third and a fourth receiving amplifier;

a first and a second impedance controlling circuit connected to the first radiating structure;

a third and a fourth impedance controlling circuit connected to the second radiating structure;

a first switching element selectively connecting the first impedance controlling circuit to the first power amplifier for transmit operation at a first transmit frequency and selectively connecting the first impedance controlling element to the first receiving amplifier for receive operation at a first receive frequency;

a second switching element selectively connecting the second impedance controlling circuit to the first power amplifier for transmit operation at a second transmit frequency and selectively connecting the second impedance controlling circuit to the second receiving amplifier for receive operation at a second receive frequency;

a third switching element selectively connecting the third impedance controlling circuit to the second power amplifier for transmit operation at a third transmit frequency and selectively connecting the third impedance controlling circuit to the third receiving amplifier for receive operation at a third receive frequency; and

a fourth switching element selectively connecting the fourth impedance controlling circuit to the second power amplifier for transmit operation at a fourth transmit frequency and selectively connecting the fourth impedance controlling element to the fourth receiving amplifier for receive operation oat a fourth receive frequency.

51. An antenna comprising:

a radiating structure having a first and a second terminal end;

a feed terminal; and

a first switching element having a first state for connecting the feed terminal to the first terminal end and a second state for connecting the feed terminal to the second terminal end.

52. The antenna of claim 51 wherein the radiating structure comprises a meanderline antenna.

53. The antenna of claim 51 further comprising a second switching element for connecting the second terminal end to ground when the first terminal end is connected to the feed terminal, and for connecting the first terminal end to ground when the second terminal end is connected to the feed terminal.

54. A method for controlling an antenna responsive to a signal produced by a power amplifier, comprising:

determining a power output of the power amplifier; and

controlling an antenna impedance to increase a power amplifier efficiency.

55. The method of claim 54 further comprising the step of a remote communications station supplying a signal for controlling the power output of the power amplifier, the step of controlling the antenna impedance further comprising controlling the antenna impedance responsive to the signal.

56. The method of claim 54 wherein controlling the antenna impedance improves a power amplifier efficiency, wherein when the power amplifier efficiency is equal to a first efficiency value the antenna impedance is controlled to increase the power amplifier efficiency to a second efficiency value.

57. A method for manufacturing an antenna, comprising:

fabricating a radiating structure;

testing the radiating structure to determine certain operating parameters of the radiating structure; and

controlling switch elements to connect one or more of a plurality of tuning components to the radiating structure to modify one or more of the operating parameters.