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 complex pulse repetition frequency generator for producing a pulse repeion frequency (PRF) signal having programmable stagger intervals. The device consists of a clock for selecting one of a series of standard clock pulses which are used to increment a counter. A comparator compares the accumlated clock pulses with a stagger data output signal produced by a data memory source. When the outputs are equal, the comparator produces a PRF output pulse. Two data memory bands are provided; a random access memory in which stagger data can be programmed by a series of switches, and a preprogrammed read-only memory. Address counters are used with each memory unit and provide capability for addressing selected memory locations from the data memory sources. A pulse width generator allows the operator to vary the pulse width and utilizes an injection lock oscillator to prevent jitter whenever a standard clock pulse is used which is not an even multiple of a hundred nanoseconds.

Abstract: A digital antenna pattern generator for producing an electrical signal to mulate any desired antenna pattern for which the device has been preprogrammed. Read only memories are utilized which are preset according to applicable intelligence data to read out desired radar antenna patterns as the memory locations are addressed in seriatim. In the preferred embodiment of the invention, the read only memories are sequentially addressed in accordance with the angular displacement across the antenna beam pattern. In an alternative embodiment, a free-running antenna pattern generator is disclosed in which the beam width, dead time and lobe rate is adjusted. Both systems convert the digital pattern generated by the read only memories into an appropriate output analog signal.