Abstract: A collision avoidance system is delineated comprising a TCAS transmitter having a feed forward path with a plurality amplifiers for providing to a TCAS transmitter output a TCAS transmitter output transmission, a feedback path coupled to the TCAS transmitter output for providing a feedback signal, and a controller for receiving the feedback signal and generating control signals for providing to one or more of the plurality of amplifiers for controlling the respective outputs of the one or more amplifiers to drive the TCAS transmitter output transmission to a predefined level.

Abstract: A microwave monolithic integrated circuit (MMIC) RF-generated bias circuit and method includes an input for receiving an RF signal. A rectifier coupled to the input and to electrical ground produces a rectified RF signal in response. A voltage divider coupled to the rectifier and to the electrical ground receives the rectified RF signal and produces a DC voltage therefrom. An output is coupled to the voltage divider for applying the DC voltage to a MMIC field effect transistor (FET) for biasing. No separate bias battery is required, and efficiency is optimized because the generated bias voltage increases to the point where the amplifier voltage begins to decrease, which in turn reduces the generated bias voltage. The derived bias voltage may be used to control other circuits (e.g., other amplifiers, oscillators, mixers, etc.) which require detection of RF presence.

Abstract: A MMIC FET mixer and method includes a RF input port for receiving a RF signal, a feedback control input for receiving a feedback signal, and a LO input port for receiving a LO signal. A feedback controller is coupled to the RF amplifier, the feedback controller for producing a controlled RF signal in response to the feedback signal. A constant current source is coupled to the feedback controller, to the RF amplifier and to the LO input port. The constant current source receives a DC offset voltage, the controlled RF signal, and the LO signal and produces an IF output signal at an IF output port. The IF output signal is proportional to the DC offset voltage, to the RF signal, and to the LO signal.

Abstract: A transmission line filter includes first and second substantially parallel transmission lines (20, 30), with alternate ends grounded and each transmission line (20, 30) coupled through a separate capacitor (50, 60) to electrical ground. A coupling capacitor (70) connects the first and second transmission lines (20, 30). A RF output (40) coupled to the second transmission line (30) outputs a filtered RF signal in response to a RF signal input to a RF input (10) on the first transmission line (20). MIC and MMIC applications using series capacitance to allow for line length to be reduced include versions of a band pass filter (FIGS. 5, 6), band stop filter (FIG. 7), and low pass filter (FIG. 9).

Abstract: A method for providing local matching elements for adjusting the characteristic impedance of local transmission line segments to more closely match the input or output impedance of the particular devices to which they couple. The method includes the step of providing a conductive bridge over the active lead of the transmission line, thereby lowering its characteristic impedance. The method can be applied to narrow transmission line segments needed to make contact to small active devices and/or MMIC's and which otherwise exhibit a substantial impedance mismatch with the small elements.

Abstract: The performance of microwave coplanar and other circuit boards is improved by providing local matching elements for adjusting the characteristic impedance of local transmission line segments to better match the input or output impedance of the particular devices to which they couple. This is accomplished by providing a conductive bridge over the active lead of the transmission line, thereby lowering its characteristic impedance. This is very useful for narrow transmission line segments needed to make contact to small active device and/or MMIC's and which otherwise exhibit a substantial impedance mismatch with such small elements.

Abstract: In a target to be towed by a vehicle, such as an airplane or the like, a radar transmitter and receiver each having separate antennas mounted in spaced apart relation at the front and back of the target, said transmitter being periodically pulsed and said receiver being turned on periodically at a given time after each pulse to produce a generally ellipsoidally shaped, shell-like sensitive volume around the target in which the radar will sense bullets, and the receiver being further constructed to sense only positive Doppler signals so that only bullets entering the sensitive volume will be scored.

Abstract: An amplifier-oscillator frequency multiplier apparatus utilizing a pair of servo-connected amplifiers which are electronically switchable to provide either a coherent amplifier or a non-coherent oscillator.