Abstract: A method and apparatus is disclosed for selectively modulating r.f. signals received/transmitted via the radiation pattern side lobes of an r.f. antenna structure. Such modulation permits discrimination between desired r.f. signal energy received via the primary radiation pattern lobe and unwanted r.f. radiation (e.g. noise, jamming or other interference signals) received/transmitted via the secondary or side lobe(s) of the radiation pattern.

Abstract: This invention allows the combination of any M of N signal inputs, combines the signals inputs in phase, and does not require switches to terminate unused inputs.Microstrip switching means provide an array of N quarter-wave tuners and an associated single, common, quarter-wave tuner that are interconnected by N semiconductor switching means. Each of the N semiconductor switches is connected with one of the N quarter-wave tuners and is operable to provide a low impedance between its connected quarter-wave tuner and the single common quarter-wave tuner.Microstrip connecting means for the microstrip switching means forms an array of N transmission lines N associated quarter-wave transformers for semiconductor switch biasing and a single transmission line.

Abstract: In order to avoid the need for individual RF down-converters in each channel of a spread spectrum adaptive array receiver, means are provided for frequency offsetting the received spread spectrum signals in each antenna array element from spread spectrum signals in the other array elements. The frequency offset signals are summed to form a broadband composite signal of spread spectrum signals separated from one another by the frequency offsets. After summing, the spread spectrum signals in the composite broadband signal are despread to form a narrowband composite signal having narrowband signals separated by the frequency offset. Since the resulting composite despread signal has a relatively narrow bandwidth, it can be passed through a single common receiver. Accordingly, the input to an adaptive array processor from the receiver is a low frequency relatively narrow signal.