A seven element X-band agile beam receiver

We describe the design, fabrication, and testing of a seven element X-band coupled oscillator based phased array receiver. An array of seven mutually injection locked S-band voltage controlled oscillators provides seven local oscillator signals that are mixed with the signals received by each of seven microstrip patch elements in the aperture. Beam-steering of the receive array is accomplished by inducing the required phase shift in the local oscillator signal associated with each array element. The downconverted in-phase intermediate frequency signals are then summed in a UHF combining network. Frequency doubling of the oscillator signals is employed to extend the scan range.