Integrated front end antenna

• US 20040227683A1
• Filed: 02/26/2004
• Published: 11/18/2004
• Est. Priority Date: 02/26/2003
• Status: Active Grant

• Current Assignee: SkyCross Co., Ltd.
• Original Assignee: SkyCross, Inc.
• Inventors: Caimi, Frank M., Innis, Donald A., Farrar, John Charles, Greer, Kerry Lane, Thursby, Michael H.
• Granted Patent: US 7,084,823 B2
• Time in Patent Office: Days
• US Class Current: 343/742
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 9/40 Element having extended radiating surface
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A radio frequency transmitting and receiving apparatus comprising a filter and an antenna, wherein the input reactance of the antenna is substantially equal in magnitude and opposite in sign to the output reactance of the filter. This reactance relationship permits the antenna and filter to be collocated and avoids transformation of the input and output impedances to the conventional 50 ohms such that the filter and antenna can be connected with a conventional 50 ohm transmission line.

Claims

1. An apparatus for receiving radio frequency signals, comprising:

an antenna having an input reactance;

a filter having an output reactance; and

wherein the input reactance and the output reactance are opposite in sign and substantially equal in magnitude.

2. The apparatus of claim 1 further comprising receiving components responsive to the filter.

3. The apparatus of claim 2 further comprising a transmission line connecting the filter and the receiving components.

4. The apparatus of claim 3 wherein the transmission line comprises one of a fiber optic transmission line and a coaxial cable transmission line.

5. The apparatus of claim 1 wherein the filter and the antenna are collocated in a communications device without an interconnecting transmission line.

6. The apparatus of claim 5 wherein the communications device comprises a hand-held communications device.

7. The apparatus of claim 1 wherein the filter comprises one or more output terminals and the antenna comprises one or more input terminals, and wherein the one or more output terminals are connected directly to the one or more input terminals.

8. The apparatus of claim 1 further comprising an antenna mast, wherein the filter and the antenna are located in an upper region of the mast.

9. The apparatus of claim 8 further comprising signal receiving components located proximate a base of the mast, and wherein the signal receiving components are connected to the filter by a transmission line.

10. The apparatus of claim 1 wherein the filter exhibits filtering characteristics, further comprising a controller for providing a signal to the filter for changing the filter characteristics.

11. An apparatus for transmitting a radio frequency signal comprising:

an antenna having first and second balanced input terminals;

a power amplifier having first and second differential output terminals; and

wherein the first differential output terminal is connected to the first balanced input terminal and the second differential output terminal is connected to the second balanced input terminal.

12. The apparatus of claim 11 further comprising transmitting components for supplying an input signal to the power amplifier, wherein the radio frequency signal is derived from the input signal.

13. The apparatus of claim 12 wherein the transmitting components are connected to the power amplifier by a transmission line.

14. The apparatus of claim 13 wherein the transmission line comprises a fiber optic transmission line.

15. The apparatus of claim 11 wherein the power amplifier and the antenna are collocated in a communications device without an interconnecting transmission line.

16. The apparatus of claim 15 wherein the communications device comprises a hand-held communications device.

17. The apparatus of claim 11 further comprising an antenna mast, wherein the power amplifier and the antenna are located in an upper region of the mast.

18. The apparatus of claim 17 further comprising signal transmitting components located proximate a base of the mast, and wherein the signal transmitting components are connected to the power amplifier by a fiber optic transmission line.

19. The apparatus of claim 18 wherein the signal transmitting components provide an excitation signal to the power amplifier over the fiber optic cable.

20. The apparatus of claim 11 wherein an output impedance of the power amplifier is substantially equal to the input impedance of the antenna.

21. The apparatus of claim 11 wherein the power amplifier exhibits an output impedance and the antenna exhibits an input impedance, and wherein the input and the output impedances are substantially equal.

22. The apparatus of claim 21 wherein the input and the output impedance are about 50 ohms.

23. The apparatus of claim 22 wherein the antenna comprises a meanderline loaded antenna.

24. An apparatus for receiving radio frequency signals:

a antenna having an input reactance and comprising first and second spaced apart elements;

an electronics module disposed between the first and the second elements, wherein the electronics module comprises a filter having an output reactance and further comprising a first output terminal connected to the first element and a second output terminal connected to the second element, and

wherein the input reactance and the output reactance are opposite in sign and substantially equal in magnitude.

25. The apparatus of claim 24 wherein the antenna comprises a meanderline loaded antenna having a top plate, and wherein the first and the second spaced apart elements comprise a first and a second spaced apart leg element of the meanderline antenna, and wherein each of the first and the second leg elements are connected to the top plate via a meanderline conductor.

26. The apparatus of claim 24 operative for receiving and transmitting radio frequency signals, wherein the electronics module further comprises a power amplifier and a switch, and wherein the switch switchably connects one of the power amplifier and the filter to the first and the second spaced apart elements, and wherein the power amplifier is switchably connected to the first and the second elements when the apparatus is operative in the transmitting mode, and the filter is switchably connected to the first and the second elements when the apparatus is operative in the receiving mode.

27. An apparatus for receiving radio frequency signals, comprising.

a substrate;

antenna elements mounted on the substrate, wherein each antenna element has an input reactance; and

a filter associated with each antenna element, wherein an output reactance of the filter is opposite in sign and substantially equal in magnitude to the input reactance of the antenna elements.

28. The apparatus of claim 27 wherein the substrate comprises a cylindrical sleeve, and wherein the antenna elements are mounted on an outer surface of the sleeve.

29. The apparatus of claim 27 wherein the substrate comprises a polyhedron comprising a plurality of surfaces, and wherein the antenna elements are mounted on one or more of the surfaces.

30. The apparatus of claim 27 further comprising a signal processing element associated with each of the antenna elements for processing the signal received by the associated antenna element, wherein each signal processing element independently processes the signal received by the associated antenna element.

31. The apparatus of claim 30 wherein the filter exhibits filter characteristics, and wherein the signal processing element comprises a controller for controlling the filter characteristics.

32. The apparatus of claim 27 wherein each antenna element is collocated with the associated filter.

33. The apparatus of claim 27 wherein each antenna element is disposed in adjacent relationship with the associated filter.

34. The apparatus of claim 27 further comprising a power amplifier associated with each antenna element, wherein the apparatus operates in a transmitting mode and in a receiving mode, and wherein the power amplifier is operative in the transmitting mode and the filter is operative in the receiving mode.

35. An apparatus for receiving and transmitting radio frequency signals, comprising:

an antenna having an input reactance;

a filter having a pass band and an output reactance, wherein the input reactance and the output reactance are opposite in sign and substantially equal in magnitude, the filter further comprising first and second input terminals;

a power amplifier having first and second differential output terminals, wherein the first differential output terminal is connected to the first input terminal and the second differential output terminal is connected to the second input terminal, and wherein a signal transmitted by the apparatus is within the pass band of the filter.

36. An apparatus for receiving and transmitting radio frequency signals, comprising:

an antenna having an input reactance;

a filter having an output reactance, wherein the input reactance and the output reactance are opposite in sign and substantially equal in magnitude;

receiving components;

a power amplifier;

a switch comprising first and second switchable terminals and a common terminal, wherein the receiving components are connected to the first switchable terminal, the power amplifier is connected to the second switchable terminal and the filter is connected to the common terminal, and wherein in a first position the switch connects the receiving components to the filter and in a second position the switch connects the power amplifier to the filter.