A demonstration of the coupled oscillator based agile beam receiver concept

The Cao-York concept of using a linear array of mutually injection locked oscillators to provide local oscillator signals for an agile beam receiver is demonstrated using a 15 circuit array of L-band voltage controlled oscillators coupled to nearest neighbors. The concept involves mixing each 1.265 GHz local oscillator (l-o) signal with a corresponding 1.950 GHz signal received by an element in an antenna aperture and combining the resulting 685 MHz intermediate frequency (i-f) signals. A normally incident wave is simulated using a power divider to provide 15 equal in-phase signals to the r-f ports of the mixers and the i-f combining is accomplished using a similar power divider in reverse. The "antenna beam" is steered through this "normally incident wave" by antisymmetrically detuning the end oscillators of the array and a plot of the i-f combiner output represents the receive beam shape. Finally, this system is used to demonstrate the Kott sidelobe suppression technique.