Abstract: In an embodiment, an antenna subsystem includes a sparse receive antenna and an electronically steerable transmit antenna. The sparse receive antenna includes an array of electronically steerable receive elements each configured to receive a respective signal having a wavelength and each spaced apart from each adjacent one of the receive elements by a respective first distance that is more than one half of the wavelength. And the electronically steerable transmit antenna includes an array of transmit elements each configured to radiate a respective signal having the wavelength and each spaced apart from each adjacent one of the transmit elements by a respective second distance that is less than one half of the wavelength. To reduce aliasing, such an antenna subsystem can be operated to filter, spatially, a receive beam pattern generated by the receive antenna with a transmit beam pattern generated by the transmit antenna.

Abstract: In an embodiment, an antenna unit includes a coupler, a phase-shifting modulator, and an antenna element. The coupler has first and second input-output ports, a coupled port, and an isolated port. The phase-shifting modulator includes a transmission medium coupled to the coupled port, a reflector, control nodes, and active devices each having a respective first device port coupled to a respective location of the transmission medium, a respective second device port coupled to the reflector, and a respective control port coupled to a respective one of the control nodes. And the antenna element is coupled to the phase-shifting modulator via the isolated port.

Abstract: An embodiment an antenna unit of an antenna array includes a signal coupler, a phase-shifting modulator, and an antenna element. The signal coupler has a first input-output port, a second input-output port, and a coupled port. The phase-shifting modulator is coupled to the coupled port of the signal coupler, and the antenna element is coupled to the phase-shifting modulator via a connection remote from the signal coupler, or via an isolated port of the signal coupler. The phase-shifting modulator is configured for both relatively low signal loss and relatively low power consumption such that the antenna array can have significantly lower C-SWAP metrics than a conventional phased array while retaining the higher performance metrics of a conventional phased array.

Abstract: An embodiment an antenna unit of an antenna array includes a signal coupler, a phase-shifting modulator, and an antenna element. The signal coupler has a first input-output port, a second input-output port, and a coupled port. The phase-shifting modulator is coupled to the coupled port of the signal coupler, and the antenna element is coupled to the phase-shifting modulator via a connection remote from the signal coupler, or via an isolated port of the signal coupler. The phase-shifting modulator is configured for both relatively low signal loss and relatively low power consumption such that the antenna array can have significantly lower C-SWAP metrics than a conventional phased array while retaining the higher performance metrics of a conventional phased array.

Abstract: In an embodiment, an antenna subsystem includes a sparse receive antenna and an electronically steerable transmit antenna. The sparse receive antenna includes an array of electronically steerable receive elements each configured to receive a respective signal having a wavelength and each spaced apart from each adjacent one of the receive elements by a respective first distance that is more than one half of the wavelength. And the electronically steerable transmit antenna includes an array of transmit elements each configured to radiate a respective signal having the wavelength and each spaced apart from each adjacent one of the transmit elements by a respective second distance that is less than one half of the wavelength. To reduce aliasing, such an antenna subsystem can be operated to filter, spatially, a receive beam pattern generated by the receive antenna with a transmit beam pattern generated by the transmit antenna.

Abstract: In an embodiment, an antenna subsystem includes a sparse receive antenna and an electronically steerable transmit antenna. The sparse receive antenna includes an array of receive elements each configured to receive a respective signal having a wavelength and each spaced apart from each adjacent one of the receive elements by a respective first distance that is more than one half of the wavelength. And the electronically steerable transmit antenna includes an array of transmit elements each configured to radiate a respective signal having the wavelength and each spaced apart from each adjacent one of the transmit elements by a respective second distance that is less than one half of the wavelength. To reduce aliasing, such an antenna subsystem can be operated to filter, spatially, a receive beam pattern generated by the receive antenna with a transmit beam pattern generated by the transmit antenna.

Abstract: In an embodiment, an antenna subsystem includes a sparse receive antenna and an electronically steerable transmit antenna. The sparse receive antenna includes an array of receive elements each configured to receive a respective signal having a wavelength and each spaced apart from each adjacent one of the receive elements by a respective first distance that is more than one half of the wavelength. And the electronically steerable transmit antenna includes an array of transmit elements each configured to radiate a respective signal having the wavelength and each spaced apart from each adjacent one of the transmit elements by a respective second distance that is less than one half of the wavelength. To reduce aliasing, such an antenna subsystem can be operated to filter, spatially, a receive beam pattern generated by the receive antenna with a transmit beam pattern generated by the transmit antenna.