Raytheon Company

Robert A Pucel

Yusuke Tajima

Robert W Bierig

James A Benjamin

Hermann Statz

James L Vorhaus

Ward S Titus

Charles F Krumm

A radio frequency circuit having at least one output terminal includes a plurality of non-linear elements, each having an output electrode. Means are provided for feeding at least one input signal to each one of the non-linear elements. The feeding means includes an electrical pathlength including at least one two port phase shifting element fed by at least the input signal, for providing a plurality of signal portions, each one fed to a corresponding one of the plurality of non-linear elements. These signal portions have a successively increasing phase shift related to the electrical pathlength of the two port phase shifting elements. The output electrodes of each non-linear element are interconnected by an input coupling means including at least one, different, two port phase shifting element, for successively electrically interconnecting the output electrode of each non-linear element. With such an arrangement, by providing two port phase shift elements in the input and output coupling means, proper phasing characteristics may be provided to such circuits without the necessity of using couplers or baluns which are generally difficult to fabricate, particularly, as broadband monolithic microwave integrated circuits.

Frequency conversion circuits

A frequency conversion circuit having first and second input signal terminals, and first and second output terminals includes a plurality of non-linear elements, each one having a pair of input electrodes and an output electrode. The first input electrode of each non-linear element is successively interconnected by a two port input coupling means, said input coupling means having a first end coupled to the first input signal terminal and a second end terminated in a terminating impedance. The output electrode of each non-linear device is successively interconnected by a two port output coupling means coupled between the pair of output terminals. An input signal is fed to the first input signal terminal and is coupled to the input coupling means and a portion of such signal is fed to the first input electrode of each non-linear device. Each portion of the input signal is provided with a successive phase shift as it propagates along the input coupling means. The second input signal terminal is fed by a second signal which is fed to the second input electrode of each non-linear element. In response to the pair of input signals, an output signal is provided at the output electrode of each one of said non-linear devices having frequency components equal to the sum and difference of the frequencies of the first and second input signals. In a preferred embodiment, the frequency propagation characteristics of the output coupling means are selected to support propagation of a first one of said sum and difference frequency components of the output signal.

A radio frequency multiplier circuit includes a first plurality of non-linear devices, each device having an input electrode and an output electrode. The input electrode of each one of the first plurality of non-linear devices is successively interconnected via a first input coupling means to a first input terminal. The multiplier further includes a second like plurality of non-linear devices, each device having an input electrode and an output electrode. The input electrode of each one of the second plurality of non-linear devices is successively interconnected via a second input coupling means to a second input terminal. A common output coupling means is provided to interconnect the output electrode of each one of the first plurality of devices with the output electrode of a corresponding one of the second plurality of devices. The multiplier further includes means for coupling a pair of signals having a 180.degree. differential phase shift to the pair of input terminals. With this arrangement, an output signal having frequency components which are even harmonics of the frequency of the input signal is provided.

Radio frequency multiplier producing an even harmonic output

A transceiver element for controlling the phase of a microwave signal passing therethrough. The transceiver element includes a plurality of switching means arranged to steer a microwave frequency signal provided by a radar system through a nonreciprocal phase shifter to a phased array antenna during a transmit mode, and to steer a microwave frequency signal received by the phased array antenna through the nonreciprocal phase shifter to the radar system during a receive mode. The microwave frequency signal passes through the phase shifter in the same direction during both the transmit and receive modes. A set of control signals is fed to such switching means and the phase shifter of the transceiver element to provide collimated and directed beams of microwave energy during the transmit mode and the receive mode.

Transceiver element for phased array antenna

A n-bit digitally controlled phase shifter for controlling the phase of an applied signal over the range of 0.degree. to 360.degree. includes n, cascade interconnected phase shifter stages. Each phase shifter stage is formed on a semi-insulating substrate having a pair of field effect transistors and a pair of transmission lines formed thereon. Each field effect transistor (FET), includes a pair of gate electrodes, a drain electrode, and a source electrode, connected in a common (grounded) source configuration. Each transmission line is coupled between a corresponding one of the drain electrodes and a common output port. The lengths of the transmission lines are selected to provide two paths having an electrical pathlength corresponding to a phase shift of .phi..sub.1 or a phase shift of .phi..sub.1 +.DELTA..phi..sub.1 where .DELTA..phi..sub.i is the phase shift increment of the i.sup.th stage. A first one of the gate electrodes of each field effect transistor is fed by the applied signal. A pair of control signals representative of one of the bits, and its compliment, is fed to the second gate electrodes of the field effect transistors, and is used to selectively couple the applied signal to one of the drain electrodes of such field effect transistors. The phase of the applied signal is shifted by propagation through the transmission line selected through control signals. Each one of the n stages, has a predetermined electrical pathlength difference for providing a selected phase shift increment (.DELTA..phi..sub.i).

N-bit digitally controlled phase shifter

A field effect transistor is provided wherein a semiconductor body has a source region and a plurality of drain regions with a gate region common to the plurality of drain regions. A common gate electrode is formed over the common gate region to control the flow of carriers to each one of the plurality of drain regions. With such arrangement an efficient multi-drain field effect transistor is provided through the use of a common gate electrode formed on the semiconductor body.

Field effect transistor

A field effect transistor having a doping concentration profile selected to linearize the relationship between the transconductance of the transistor and the level of a gate voltage fed to the gate electrode of such transistor over the operating range of such voltage. A first doping concentration profile is 'spike-shaped' so that the bottom of the depletion zone and hence the transconductance is substantially invariant with gate voltage level. A second doping concentration profile, N(x), varies substantially as 1/x.sup.3 (where x is the depth from the surface of the transistor) over the operating range of the bottom of the depletion zone.

A high-frequency, high-power FET constructed upon a planar substrate with a repeated pattern of gate, source, and drain connections wherein any two are interconnected with metallization layers adjacent to and separated from the semiconductor substrate. The third element is interconnected with an overlay metallization layer separated from the lower two metallization layers by an insulating dielectric. The overlay layer is preferably grounded for minimum feedback capacitance.

Overlay metallization multi-channel high frequency field effect

A Read-type avalanche diode having a low noise measure and capable of attaining output signal powers of one watt or more. An effective injection current is defined as the conduction current in the avalanche zone in the absence of avalanche multiplication including therein any tunneling current. The noise measure of the diode is minimized by increasing the defined effective injection current with disclosed techniques. In one embodiment, the effective injection current is increased by the presence of traps located in the avalanche region. In another embodiment, a Schottky barrier contact having a low work function is provided. Surface states of the avalanche region are also varied to produce the desired increase. Increased effective injection current may also be produced in a device with preferred heat flow properties. The noise performance of both oscillator and amplifier circuits is improved with the invention.

Low noise read-type diode

A high-frequency, high-power FET constructed upon a planar substrate with a repeated pattern of gate, source, and drain connections wherein any two are connected with metallization layers adjacent to and separated from the semiconductor substrate. The third element is interconnected with an overlay metallization layer separated from the lower two metallization layers by an insulating dielectric. The overlay layer is preferably grounded for minimum feedback capacitance.

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Needham, MA, United States of America

Robert A Pucel