Multifunctional microstrip antennas

• US 4,728,960 A
• Filed: 06/10/1986
• Issued: 03/01/1988
• Est. Priority Date: 06/10/1986
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Lo, Yuen T.
• Primary Examiner(s): Davie, James W.
• Assistant Examiner(s): Le, Hoanganh
• Application Number:
  US06/872,587
• Time in Patent Office: 630 Days
• Field of Search: 343/700 MS File, 343/701
• US Class Current: 343/700.0MS
• CPC Class Codes: G01S 7/038 Feedthrough nulling circuits
• CPC Class Codes: H01Q 1/525 between emitting and receiving antennas
• CPC Class Codes: H01Q 25/001 Crossed polarisation dual antennas orthomode horns H01Q13/0258; cross-polarised rear feeds H01Q19/136; orthomode transducers H01P1/161
• CPC Class Codes: H01Q 9/0428 radiating a circular polarised wave

Abstract

A microstrip antenna system that is capable of simultaneously transmitting an outgoing circularly polarized wave while receiving an incoming circularly polarized wave using a microstrip patch antenna element and a signal processing network is disclosed. The signal processing system connects the antenna element to a transmitter and receiver and produces a phase-shifted transmitted signal in order to isolate the receiver from the transmitted signal by nulling it.

Claims

1. A multifunctional microstrip antenna system capable of simultaneously transmitting an outgoing circularly polarized wave and receiving an incoming circularly polarized wave when said incoming circularly polarized wave has an opposite sense of polarization with respect to said outgoing circularly polarized wave, said multifunctional microstrip antenna system comprising:

a signal source which generates said outgoing circularly polarized wave;

a microstrip patch antenna element which transmits said outgoing circularly polarized wave while simultaneously receiving said incoming circularly polarized wave wherein said microstrip patch antenna element comprises a truncated rectangular patch element which has at least one set of opposing corners removed, said truncated rectangular patch element having an input port which receives said outgoing circularly polarized wave thereby, said truncated rectangular patch element having an output port which outputs simultaneously said outgoing circularly polarized wave as well as said incoming circularly polarized wave;

an attenuating means which is electrically connected to said signal source and said microstrip patch antenna element to conduct said outgoing circularly polarized wave from said signal source to said microstrip patch antenna element while providing an attenuation to said outgoing circularly polarized wave;

a phase shifter which is electrically connected with said signal source and produces a phase-shifted outgoing circularly polarized wave which when combined with said outgoing circularly polarized wave acts to null it, wherein said phase shifter comprises a fixed phase shifter which provides a fixed phase shift to said outgoing circularly polarized wave to produce said phase-shifted outgoing circularly polarized wave;

a directional coupler which is electrically connected with said phase shifter and said microstrip patch antenna element, said directional coupler thereby receiving said outgoing circularly polarized wave which is nulled with said phase-shifted outgoing circularly polarized wave as well as receiving conducting and outputting said incoming circularly polarized wave; and

a receiver which is electrically connected to and receives said incoming circularly polarized wave from said directional coupler.

2. A multifunctional microstrip antenna system capable of simultaneously transmitting an outgoing circularly polarized wave and receiving an incoming circularly polarized wave when said incoming circularly polarized wave has an opposite sense of polarization with respect to said outgoing circularly polarized wave, said multifunctional microstrip antenna system comprising:

a signal source which generates said outgoing circularly polarized wave;

a microstrip patch antenna element which has an input port which is electrically connected to and receives said outgoing circularly polarized wave from said signal source so that it transmits said outgoing circularly polarized wave while simultaneously receiving said incoming circularly polarized wave, said microstrip patch antenna element comprising a rectangular patch antenna element which has an output port over which it outputs said outgoing circularly polarized wave, and wherein said microstrip patch antenna element further comprises a truncated rectangular patch element which has at least one set of opposing corners removed;

a phase shifter which is electrically connected with said signal soiurce and produces a phase-shifted outgoing circularly polarized wave which when combined with said outgoing circularly polarized wave acts to null it;

a directional coupler whichis electrically connected with said phase shifter and said microstrip patch antenna element, said directional coupler thereby receiving said outgoing circularly polarized wave which is nulled with said phase-shifted outgoing circularly polarized wave as well as receiving conducting and outputting said incoming circularly polarized wave; and

a receiver which is electrically connected to and receives said incoming circularly polarized wave from said directional coupler.