Phased-array antenna filter and diplexer for a super economical broadcast system

• US 8,344,826 B2
• Filed: 04/21/2009
• Issued: 01/01/2013
• Est. Priority Date: 04/21/2008
• Status: Expired due to Fees

• Current Assignee: Radio Innovation Sweden AB, SPX Corporation
• Original Assignee: SPX Corporation
• Inventors: Rossiter, Chris, Dunning, Robert, Johnson, Torbjorn
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): GLENN, KIMBERLY E
• Application Number:
  US12/427,674
• Publication Number:
  US 20090284325A1
• Time in Patent Office: 1,351 Days
• Field of Search: 333/134, 333/135, 333/212, 333126-129
• US Class Current: 333/134
• CPC Class Codes: H01P 1/208 Cascaded cavities; Cascaded resonators inside a hollow waveguide structure H01P1/205 takes precedence
• CPC Class Codes: H01P 1/2084 with dielectric resonators
• CPC Class Codes: H01P 1/2138 using hollow waveguide filters H01P1/2131 takes precedence

Abstract

A phased-array antenna filter and diplexer for a super economical broadcast system are provided. The filter and diplexer includes a signal divider tee diplexer, a receive filter and a transmit filter. The diplexer includes a tee branch point, an antenna port, a transmit port and a receive port. The receive filter includes a flat, multi-pole bandpass filter, an input port and an output port, where the input port is coupled to the diplexer receive port to define a receive signal path, from the tee branch point to the receive input port, that has a length of approximately one quarter receive wavelength. The transmit filter includes a folded, multi-pole bandpass filter, an input port and an output port, where the output port is coupled to the diplexer transmit port to define a transmit signal path, from the tee branch point to the transmit output port, that has a length of approximately one quarter transmit wavelength.

Claims

1. A phased-array antenna filter and diplexer for a cellular communication system, comprising:

a signal divider tee diplexer including a tee branch point, an antenna port, a diplexer transmit port and a diplexer receive port;

a receive filter including a maximally-flat, multi-pole bandpass filter, a receive input port and a receive output port, the receive input port coupled to the diplexer receive port to define a receive signal path, from the tee branch point to the receive input port, having a length of approximately one quarter receive wavelength; and

a transmit filter including a folded, multi-pole bandpass filter, a transmit input port and a transmit output port, the transmit output port coupled to the diplexer transmit port to define a transmit signal path, from the tee branch point to the transmit output port, having a length of approximately one quarter transmit wavelength,

wherein the antenna port transfers signal energy bidirectionally with at least one radiator stack of an antenna.

2. The phased-array antenna filter and diplexer of claim 1, wherein the diplexer antenna port transfers signal energy bidirectionally with two of four radiator stacks of an antenna.

3. The phased-array antenna filter and diplexer of claim 1, wherein the diplexer includes a common leg, a transmit leg, and a receive leg.

4. The phased-array antenna filter and diplexer of claim 3, wherein the transmit leg of the diplexer appears as an open circuit to signals at a frequency range of the receive leg.

5. The phased-array antenna filter and diplexer of claim 3, wherein the receive leg of the diplexer appears as an open circuit to signals at a frequency range of the transmit leg.

6. A phased-array antenna filter and diplexer for a cellular communication system, comprising:

a signal divider tee diplexer including a tee branch point, an antenna port, a diplexer transmit port and a diplexer receive port;

a receive filter including a maximally-flat, multi-pole bandpass filter, a receive input port and a receive output port, the receive input port coupled to the diplexer receive port to define a receive signal path, from the tee branch point to the receive input port, having a length of approximately one quarter receive wavelength;

a transmit filter including a folded, multi-pole bandpass filter, a transmit input port and a transmit output port, the transmit output port coupled to the diplexer transmit port to define a transmit signal path, from the tee branch point to the transmit output port, having a length of approximately one quarter transmit wavelength; and

a unitized envelope enclosing the diplexer, the transmit filter and the receive filter.

7. The phased-array antenna filter and diplexer of claim 6, wherein the unitized envelope is a unitary machined or cast block of a free-machining or castable/machineable aluminum alloy.

8. The phased-array antenna filter and diplexer of claim 7, further comprising resonator elements that are oriented in parallel positions, compatible with milling a respective chambers of the unitized envelope from one side.

9. A phased-array antenna filter and diplexer for a cellular communication system, comprising:

a signal divider tee diplexer including a tee branch point, an antenna port, a diplexer transmit port and a diplexer receive port;

a receive filter including a maximally-flat, multi-pole bandpass filter, a receive input port and a receive output port, the receive input port coupled to the diplexer receive port to define a receive signal path, from the tee branch point to the receive input port, having a length of approximately one quarter receive wavelength; and

a transmit filter including a folded, multi-pole bandpass filter, a transmit input port and a transmit output port, the transmit output port coupled to the diplexer transmit port to define a transmit signal path, from the tee branch point to the transmit output port, having a length of approximately one quarter transmit wavelength,

wherein the receive filter is a maximally-flat 7-pole bandpass filter and includes cascaded, serpentine-arranged, and resonator-loaded tuned cavities, with bandwidth-determining tuning screws disposed in coupling windows between the cavities.

10. The phased-array antenna filter and diplexer of claim 9, wherein the receive filter includes at least one transmission zero realized through inductive cross-coupling from a predetermined number of additional windows.

11. The phased-array antenna filter and diplexer of claim 9, wherein the receive filter is tunable to lower out-of-band rejection.

12. A phased-array antenna filter and diplexer for a cellular communication system, comprising:

a signal divider tee diplexer including a tee branch point, an antenna port, a diplexer transmit port and a diplexer receive port;

a receive filter including a maximally-flat, multi-pole bandpass filter, a receive input port and a receive output port, the receive input port coupled to the diplexer receive port to define a receive signal path, from the tee branch point to the receive input port, having a length of approximately one quarter receive wavelength;

a transmit filter including a folded, multi-pole bandpass filter, a transmit input port and a transmit output port, the transmit output port coupled to the diplexer transmit port to define a transmit signal path, from the tee branch point to the transmit output port, having a length of approximately one quarter transmit wavelength; and

the receive filter further comprises;

a first conductive link from a diplexer receiver-side port to a first receiver filter resonator; and

a second conductive link from a last receiver filter resonator to a low-noise amplifier.

13. The phased-array antenna filter and diplexer of claim 12, wherein an increased number of poles and an increased cavity size narrows a receive reject band.

14. A phased-array antenna filter and diplexer for a cellular communication system, comprising:

a signal divider tee diplexer including a tee branch point, an antenna port, a diplexer transmit port and a diplexer receive port;

a receive filter including a maximally-flat, multi-pole bandpass filter, a receive input port and a receive output port, the receive input port coupled to the diplexer receive port to define a receive signal path, from the tee branch point to the receive input port, having a length of approximately one quarter receive wavelength; and

a transmit filter including a folded, multi-pole bandpass filter, a transmit input port and a transmit output port, the transmit output port coupled to the diplexer transmit port to define a transmit signal path, from the tee branch point to the transmit output port, having a length of approximately one quarter transmit wavelength,

wherein the transmit filter is a folded 6-pole bandpass filter including a conductive link from a last transmitter filter resonator to a diplexer transmit-side port.

15. The phased-array antenna filter and diplexer of claim 14, wherein the folded 6 pole transmit filter includes a cross-coupled filter having two low-side transmission zeroes.

16. The phased-array antenna filter and diplexer of claim 15, wherein the transmit filter includes:

complex cross-coupling with a capacitive and an inductive zero below a passband;

cascaded, serpentine-arranged, and resonator-loaded tuned cavities within the passband; and

tunable coupling windows.