Abstract: An RF band receiver for concurrently monitoring a plurality of contiguous channels within the RF spectrum to unambiguously detect time-coincident signals. The receiver includes a plurality of transmission paths feeding a like number of digital, mixed-base code channels. Each mixed-base code channel includes a harmonic mixer, an IF amp, a plurality of bandpass-filters and a like plurality of detectors. The outputs of the detectors for each mixed-base code channel are fed to a frequency sorter whose output is a digital frequency word which indicates the frequency(s) of the received signal(s).

Abstract: A method and apparatus for electronically simulating the transmit-receive gnal path of doppler radar during a target encounter in a simulator. It is an end-to-end fuze (radar) test from RF "in" to video "out". Target signature data is collected at a reduced relative encounter velocity from the actual target. The modified pulse doppler radar produces two orthogonal signals which define the complex received radar signal. These signals are then recorded. The missile radar to be tested is coupled to the simulator which simulates an actual missile to target encounter. During the test the PROMs are clocked into RF components in an RF Loop and clock counter is started. When the radar threshold is exceeded, a radar video output function stops the counter. By correlating the number of clock pulses counter to the distance marks traveled along the missile trajectory, missile radar function with respect to target location data is obtained and missle lethality computed.

Abstract: Method and apparatus for filtering high data rate signals, using a digital type filter, without requiring an analog-to-digital converter or the multiplicaton of digital signals. The incoming signal is wideband filtered and then hard limited to produce a constant amplitude signal having either a first or second instantaneous value. The constant amplitude signal is periodically sampled and stored in a multi-bit digital shift register as logic 1 or 0 signals. In one embodiment, the logic 1 or 0 signals stored in the shift register bits are periodically read out, multiplied by respective weighting constants, and summed to provide a filtered analog output signal. In another embodiment, the combination of logic 1 and 0 signals stored in the shift register are periodically sampled and used to address a memory, which outputs a digital signal which is the calculated value of weighted sum for that shift register combination.

Abstract: A method of apparatus for determining the rectangular coordinate direction angles of a source of radio signals received by a four arm log spiral antenna and then processed by a beam-forming network to simultaneously generate both sum and difference modes. The sum and difference IF signals are heterodyned to a sum IF signal .SIGMA. and a difference IF signal .DELTA.. The .SIGMA. and .DELTA. signals are combined in an IF network to provide three IF signals, namely .SIGMA.+.DELTA., .SIGMA.-j .DELTA. and j .SIGMA., which are thereafter amplitude limited by respective limiting amplifiers. The three limited signals are processed by two phase detectors, which generate voltages E.sub.x and E.sub.y corresponding respectively to the sine of the phase angles of the limited signals .SIGMA.+.DELTA. and .SIGMA.-j .DELTA. relative to the limited signal j .SIGMA.. Since each combination of the voltages E.sub.x and E.sub.

Abstract: A method and apparatus for receiving and detecting pulsed RF signals within first frequency band. Incoming pulsed RF signals are supplied to a linear amplifier which amplifies any of the signals within a broader second frequency band. The pulsed RF output signals of the amplifier are supplied to an in-band signal detection circuit controlling switches in the outputs of a first video detector and a frequency discriminator which are also supplied with the amplifier output signals, so that output video and frequency signals are provided only for pulsed RF signals within the first frequency band.

Abstract: A method and apparatus for eliminating the sidelobe ambiguity in the range esponse of an FM-CW radar. An FM-CW signal with a periodic modulation frequency is transmitted and reflected from a target, received and combined with a sample of the transmitted signal to provide a combination signal. A portion of this combination signal including a selected harmonic and next adjacent harmonic is amplified and mixed with reference signals comprising the selected harmonic and next adjacent harmonic to provide two separate difference signals. These signals are in turn low pass filtered and further mixed to provide a range response with a mainlobe of one polarity and all side lobes of an opposite polarity. The energy under the mainlobe is detected and integrated to provide a voltage signal. When this voltage signal reaches a preset threshold level a further signal is generated.