Abstract: A pulse repetition interval generator with stagger circuit for providing a ulse repetition interval signal. The pulse repetition interval generator can be used with a device for generating simulated antenna scan patterns of conventional search radar antennas and comprises a source of clock pulses, a counter circuit, a repetition interval setting means, pulse generator means and a pulse width determining means.

Abstract: Apparatus for generating pulses having selectable pulse width and selecta pulse repetition interval which may be used as a pulse repetition interval generator in a radar signal simulator. Each pulse is initiated by a clocked counter when it reaches a predetermined count from a preselected initial count. The initial count is determined by data stored in a read-only-memory which is selectably loaded into the counter to provide a variable initial count. Another clocked counter which is enabled by the leading edge of the pulse then terminates the pulse when it reaches a predetermined count from a preselected initial count.

Abstract: A device for generating simulated antenna scan patterns of conventional sch radar antennas comprising an antenna scan generator for providing a low frequency a-c signal and a pulse repetition interval generator with stagger circuit for providing a pulse repetition interval signal. An RF carrier signal modulated by the pulse repetition interval signal is amplitude modulated by the low frequency a-c signal for generating the simulated antenna scan pattern.

Abstract: A microwave isolation switch comprising a D.C. bias source and a diode nerk for passing a microwave signal from an input port to an output port when the D.C. bias source is in a negative mode of operation and for reflecting and terminating the microwave signal when the D.C. bias source is in a positive mode of operation.

Abstract: A microwave cross-over switch comprising first and second D.C. bias sources nd a diode network for switching first and second microwave signals to first or second output ports in response to the mode of operation of the first and the second D.C. bias sources.

Abstract: A programmable microwave modulator for controlling the amplitude of a micave signal versus time. A programmed driver generates a linear analog signal that has a predetermined amplitude pattern and time period. The linear analog signal from the programmable driver passes through a linearized current driver before inputting a PIN attenuator. The linearized current driver takes the antilogarithm of the linear analog signal, thus compensating for the logarithmic nonlinearity of the PIN attenuator. A radio frequency signal from a receiving antenna inputs the PIN attenuator and is attenuated as a function of the amplitude pattern of the linear analog signal. The PIN attenuator outputs the attenuated radio frequency signal.

Abstract: A multiple polarization switch which provides horizontal, vertical, rightnd circular and left-hand circular polarization from a single microwave source for use with a quadrature feed antenna. The device is comprised of a hybrid coupler, isolation switch, and cross-over switch with a narrow band design accomplished by shunt pin diodes controlled by external D.C. current sources of the proper polarity.