초록 ▼

A module disposed at each radiating element of a phased array antenna, the module having a limiter, a low-noise amplifier and a phase shifter. One embodiment includes a DPDT switch to permit use of a common phase shifter on transmit and receive. On transmit, the DPDT switch is thrown in a position t

A module disposed at each radiating element of a phased array antenna, the module having a limiter, a low-noise amplifier and a phase shifter. One embodiment includes a DPDT switch to permit use of a common phase shifter on transmit and receive. On transmit, the DPDT switch is thrown in a position that connects the phase shifter directly to the radiating element. On receive, the DPDT switch is thrown in a position that connects the radiating element through the limiter and low noise amplifier and then to the phase shifter. Another embodiment uses a four-port circulator in place of the DPDT switch, and uses separate phase shifters for transmit and receive. A semi-active module for a constrained feed array uses both a DPDT switch and a circulator and uses a common transmit/receive phase shifter. A semi-active module for a space-fed array uses two DPDT switches, a single phase-shifter and limiter/low-noise amplifier and two antenna elements; one of receive, and one for retransmit. Another module employs a four-port circulator, separate transmit and receive phase shifters, and separate transmit and receive beamforming networks. In a monopulse radar transmitter, a module using a four-port circulator and a separate receive diode phase shifter, limiter and low-noise amplifier is used with a receive monopulse feed, transmit ferrite phase shifters and a transmit series feed.

대표청구항 ▼

A semi-active phased array antenna having individual semi-active modules disposed adjacent individual antenna elements for selectively interconnecting the antenna elements with a single transmit/receive feed line in a first mode on transmit and in a second mode on receive, said modules comprising: a

A semi-active phased array antenna having individual semi-active modules disposed adjacent individual antenna elements for selectively interconnecting the antenna elements with a single transmit/receive feed line in a first mode on transmit and in a second mode on receive, said modules comprising: a receive circuit internal to said module including a limiter and a low noise amplifier; a phase shifter disposed within said module; a single transmit/receive feed line connected to one end of said phase shifter; and switch means in said module connected to the other end of said phase shifter and connected to its associated antenna element and arranged to selectively switch between said first and second modes, said switch means connecting its associated antenna element to said feed line by way of said phase shifter on transmit, said switch means connecting its associated antenna element to said feed line by way of said receive circuit and said phase shifter on receive; whereby said phase shifter is included in the circuit from said antenna element to said transmit/receive feed line both on transmit and receive, and whereby said limiter and said low noise amplifier are bypassed on transmit.