Raytheon Company

Auriga Measurement Systems, LLC

Yusuke Tajima

Robert A Pucel

Toshikazu Tsukii

Manfred J Schindler

Steven A Mulawski

John R Muir

Cheryl V Liss

James Sozanski

Robert G Gels

Aryeh Platzker

Ward S Titus

J Bradford Cole

Peter Bacon

Shiou L Chu

Mark A Royer

Erick A Olsen

Qin Shen-Schultz

Daniel L Kaczman

Circuits and techniques to linearize the operation of an RF power amplifier are described. A linearizer circuit may include a non-amplification signal path which includes a delay line and an amplification signal path which includes at least one amplifier stage. In some embodiments, the amplification signal path may include an odd number of amplification stages. The linearizer may be used to precondition an input signal of an RF power amplifier in a manner that improves the overall linearity of operation.

Linearization circuit and related techniques

An envelope tracking power amplifier uses signal cancellation techniques to provide isolation between RF signals and envelope signals, without the use of filters. In this manner, the envelope tracking power amplifiers are capable of operating with envelope signals that are at or near the frequency of the corresponding RF signals. In at least one embodiment, a double balanced power amplifier is provided that includes a balanced RF input port, a balanced RF output port, and a balanced envelope input port. The balanced nature of the amplifier results in ports of the amplifier forming virtual grounds with respect to signals at other ports. In some other embodiments, a single balanced amplifier is provided that provides isolation between ports thereof.

Envelope tracking amplifier

A radio frequency (RF) switch circuit includes switching devices coupled at a common node and a floating control signal circuit (CSS) coupled to the control electrodes of the switching devices and the common node and configured to isolate RF signals from the CSS and configured to provide differential voltage signals to the common node and each of the control electrodes.

High power radio frequency (RF) switch

An amplifier circuit includes a pair of amplifying devices, a first balun coupled between an input port of the amplifier circuit and RF input ports of the pair of amplifying devices and a second balun coupled between RF output ports of the pair of amplifying devices and an output port of the amplifier circuit wherein the first and second baluns are configured such that the amplifier circuit operates under open condition for signals at a second harmonic frequency even when the second harmonic frequency is within an operating frequency band of a fundamental frequency of the amplifier circuit. In one embodiment, the amplifier circuit includes a bypass circuit which selectively couples balun ports to ground such that in response to a first control signal, the amplifier circuit operates in an amplifying mode and in response to a second control signal, the amplifier circuit operates in a bypass mode.

Amplifier circuit

A power supply stage includes a digital signal generation means to generate n bit digital signal, a selection means for power supply voltages in dependence on n bit digital signal and an adjusting means for receiving the selected power supply voltage and the envelope signal and adapted to generate an adjusted selected power supply voltage tracking the envelope signal.

RF amplifier modulation circuit and related techniques

A switchable, dual channel frequency converter is provided. The converter includes a semiconductor body having formed as a monolithic microwave integrated circuit: a pair of input signal channels; a pair of output signal channels; and, a mixer and multiplexer means, disposed between the pair of input signal channels and the pair of output signal channels, for converting the frequency of signals fed to the pair of input signal channels to a different frequency and for directing the frequency converted signals to the pair of output signal channels selectively in accordance with a control signal. The mixer and multiplexer means includes: a pair of mixers coupled to the pair of input signal channels and a common local oscillator signal; and a multiplexer network. The mixers covert the radio frequency of the signals in the pair of input signal channels into a corresponding pair of intermediate frequency signal channels. The multiplexer network includes a pair of input ports fed by the pair of intermediate frequency signal channels and a pair of output ports which feed the pair of output signal channels. A control signal is fed to the multiplexer network. The power transfer of the intermediate frequency signals through the multiplexer network to the output signal channels is substantially the same (i.e., less than 0.5 db difference) independent of the state of the control signal.

Radio frequency signal frequency converter

A power combiner which maintains substantially constant power combining efficiency with variable output power includes a set of unit amplifiers that are coupled by the power combiner. The power combiner includes a first plurality of a quarter wavelength transmission line sections coupled to the output of each unit amplifier. The second end of each one of the first plurality of quarter wavelength transmission line sections are successively coupled by a corresponding second plurality of quarter wavelength transmission line sections, with the succeeding or last one of said unit amplifiers having its quarter wavelength transmission line section coupled to an output terminal. The power combiner permits unit amplifiers in the amplifier module to be switched off in succession as less output power is required while maintaining substantially constant power combining efficiency, and hence substantially constant D.C. to r.f. conversion efficiency.

Amplifier having substantially constant D.C. to r.f. conversion

A radio frequency matrix amplifier includes an input propagation network for successively connecting input electrodes of a first plurality of transistors. Output electrodes are successively coupled by an intermediate propagation network. The amplifier also includes a second plurality of transistors, having input electrodes successively coupled by the intermediate propagation network and output electrodes successively coupled by an output propagation network. A bias circuit for the amplifier includes an inductor connected between a last one of the second plurality of transistors and the intermediate propagation network and a plurality of capacitors disposed to connect reference electrodes of the second plurality of transistors to a reference potential. With this arrangement stages are connected in series for D.C. potentials and in cascade for r.f. potentials. In a preferred embodiment, capacitors are disposed between the input electrodes of each of the second plurality of transistors and the output electrodes of each of the first plurality of transistors to D.C. isolate the stages, and a voltage divider is disposed between the drain bias terminal and a reference potential for balancing input voltages at each of the inputs of the first plurality of transistors substantially independently of current through the output electrodes of each of the plurality of transistors.

Biasing networks for matrix amplifiers

Transversal and recursive filters having an input propagation lumped element network with a band pass filter response, a low pass filter response, or a high pass filter response, and an output propagation network having a low pass frequency response, a high pass frequency response, or a band pass frequency response are described. Weighting means including a plurality of field effect transistors are used to successively couple the input propagation network and the output propagation network. The general shape or response of the transversal filter is provided by choosing the characteristics of the input and output propagation networks in relation to the desired filter response. With the general shape provided by the propagation networks rather than only by the transversal elements, fewer transversal elements are required to provide a desired response. Thus, the transversal filters are smaller which increases the manufacturability of the circuit and reduces the cost of the circuit particularly when fabricated as a monolithic microwave integrated circuit. Further, for transversal filters having a bandpass characteristic, harmonic sub-bands generated at high frequencies are eliminated by use of lumped element networks having cutoff frequencies coinciding with the frequency skirts or bandedges of the filter.

Transversal and recursive filters useable in a diplexer

A programmable attenuator includes a plurality of field effect transistors (FETS) arranged together to provide an attenuation network. Each one of the FETS has a plurality of cell portions, each cell portion having drain, gate and source regions, the source and drain regions of the cell portions being connected in parallel. A first selected portion of the gate regions of each one of said FETS is connected to a gate electrode. A second selected remaining portion of the gate regions of each one of the FETS has the gate regions thereof physically isolated from the gate electrode. A signal fed to the gate electrode of each FET is distributed to the connected gate regions of each field effect transistor. In response to such signal, the total drain-source resistance of such FET is changed between a predetermined low value and a predetermined high value, with the resistance of the predetermined high value being determined, in part, by the number of such isolated gate regions.

Monolithic programmable attenuator

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 programmable attenuator includes a plurality of field effect transistors (FETS) arranged together to provide an attenuation network. Each one of the FETS has a plurality of cell portions, each cell portion having drain, gate and source regions, the source and drain regions of the cell portions being connected in parallel. A first selected portion of the gate regions of each one of said FETS is connected to a gate electrode. A second selected remaining portion of the gate regions of each one of the FETS has the gate regions thereof isolated from the gate electrode. A signal fed to the gate electrode of each FET is distributed to the connected gate regions of each field effect transistor. In response to such signal, the total drain-source resistance of such FET is changed between a predetermined low value and a predetermined high value, with the resistance of the predetermined high value being determined, in part, by the number of such isolated gate regions.

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 radio frequency circuit for coupling radio frequency (r.f.) energy between an input port and a pair of output ports with an isolation port being provided for reflected energy. The circuit includes a pair of strip conductors, each one thereof having first surface portions dielectrically spaced a first predetermined distance from a ground plane conductor and second surface portions dielectrically spaced a second different predetermined distance from the ground plane conductor. The first surface portions of one of the pair of strip conductors are electromagnetically coupled, through the dielectric, to the second surface portions of the other one of the pair of strip conductors. In one embodiment, intermediate portions of the pair of strip conductors are interlaced with end portions thereof providing a corresponding one of the aforementioned ports. More particularly, a first plurality of successively spaced strip conductor portions, and a second like plurality of successively spaced strip conductor portions are dielectrically separated from the first plurality of spaced strip conductor portions. Each intermediate one of the first and second plurality of strip conductor portions is connected to a pair of strip conductors flanking the strip conductor portion electromagnetically coupled thereto, to provide a pair of dielectrically separated, interlaced, strip conductors. First and last ones of the first and second plurality of strip conductor portions are coupled to the aforementioned ports. In a second embodiment, end portions of the pair of strip conductors are interlaced and said end portions provide a corresponding one of such aforementioned ports.

Growing community of inventors

Acton, MA, United States of America

Yusuke Tajima