Abstract: A temperature compensated resonator (15) and method for making the temperature compensated resonator (15). The temperature compensated resonator (15) has a substrate (110) including a cavity (120, 160) and a resonator layer (150). A bonding medium (159, 160) couples the substrate (110) to the resonator layer (150). The resonator layer (150) is bonded atop the cavity (120, 160). A conductor (215) is included on the resonator layer (150). The conductor (215) heats the resonator layer (150) in response to a current passing through the conductor (215).

Abstract: A high quality factor resonator (15) including a substrate (110) and a resonator layer (150). The resonator layer includes a first electrode (157). The resonator layer (150) is disposed on a surface of the substrate (110). The first electrode (157) is disposed on a distal surface of the resonator layer (150). A cavity (120) is disposed between the substrate (110) and the resonator layer (150) and a second electrode (159) is disposed on the substrate (110) and on a surface of the cavity (120) remote from the resonator layer (150) and is separated from the resonator layer (150) by a thin gap.

Abstract: A temperature compensated resonator (15) and method for making the temperature compensated resonator (15). The temperature compensated resonator (15) has a substrate (110) including a cavity (120, 160) and a resonator layer (150). A bonding medium (159, 160) couples the substrate (110) to the resonator layer (150). The resonator layer (150) is bonded atop the cavity (120, 160). A conductor (215) is included on the resonator layer (150). The conductor (215) heats the resonator layer (150) in response to a current passing through the conductor (215).

Abstract: A sensor (10, 40) for measuring the ratio of fluids or other materials in mixture (12) utilizes a coplanar resonator. The resonator has an outer conductor or conductor plane (17, 41) that is on a semiconductor substrate (11). The conductor plane (17, 41) has an opening (18, 48) that exposes a portion of the surface of the substrate. An inner conductor or sensing element (19, 42) is formed on the exposed surface within the opening (18, 48) so that the conductor plane (17, 41) and the sensing element (19, 42) are coplanar. The sensing element (19, 42) is coupled to an input (22) of a transistor (21) to form an oscillator. The oscillator frequency varies as the ratio of materials in the mixture (12) varies.

Abstract: A filter (500) including a first resonator (505) coupled in shunt with a first port (507), a first bridging network (510) coupled between the first port (507) and a first node (509), a second resonator (515) coupled in shunt with the first node (509) and a second port (547) coupled to the first node (509). The first (505) and second (515) resonators each include acoustic resonators (15) and the first bridging network (510) has an electrical length .THETA. at a frequency .omega. in a system having a characteristic admittance Y in accordance with .omega.C.sub.o =Ycot.THETA. where C.sub.o is a shunt capacitance including the clamping capacitance of the first resonator (505) and .omega. is a center frequency of the filter (500).

Abstract: A semiconductor substrate with electronic circuitry (e.g., a transmitter or receiver) formed thereon and including interconnects. A ferrite disk bonded to the substrate so as to interact with the interconnects, when the ferrite disk is activated by a substantially constant magnetic field thereacross, to provide frequency selectivity within the electronic circuitry. A permanent magnet positioned adjacent to the ferrite disk to provide a substantially constant magnetic field across the ferrite disk so that the magnetic field produces resonance in the ferrite disk.

Abstract: A high quality factor resonator (15) including a substrate (110) and a resonator layer (150). The resonator layer includes a first electrode (157). The resonator layer (150) is disposed on a surface of the substrate (110). The first electrode (157) is disposed on a distal surface of the resonator layer (150). A cavity (120) is disposed between the substrate (110) and the resonator layer (150) and a second electrode (159) is disposed on the substrate (110) and on a surface of the cavity (120) remote from the resonator layer (150) and is separated from the resonator layer (150) by a thin gap.

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 sensor (10, 40) for measuring the ratio of fluids or other materials in mixture (12) utilizes a coplanar resonator. The resonator has an outer conductor or conductor plane (17, 41) that is on a semiconductor substrate (11). The conductor plane (17, 41) has an opening (18, 48) that exposes a portion of the surface of the substrate. An inner conductor or sensing element (19, 42) is formed on the exposed surface within the opening (18, 48) so that the conductor plane (17, 41) and the sensing element (19, 42) are coplanar. The sensing element (19, 42) is coupled to an input (22) of a transistor (21) to form an oscillator. The oscillator frequency varies as the ratio of materials in the mixture (12) varies.

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 four port coupler includes a first port adapted to impedance match to a first impedance Z.sub.o, a second port adapted to impedance match to a second impedance Z.sub.1 different than the first impedance, a third port adapted to impedance match to the first impedance and a fourth port adapted to impedance match to the second impedance.

Abstract: An impedance transforming three-port power divider/combiner includes first, second, and third lumped elements (e.g. 54, 55, and 56). The first lumped element (54) couples the first port (51) and electrical ground. The second lumped element (55) couples the first and second ports (51 and 52), and the third lumped element (56) couples the first and third ports (51 and 53). A resistor (59) is coupled between the second and third ports (52 and 53). Capacitors (57 and 58) couple the second port (52) and the third port (53) to electrical ground. A signal input to the first port (51) results in identical divided output signals at the second and third ports (52 and 53). Signals input to the second and third ports (52 and 53) result in a combined output signal at the first port (51).

Abstract: An apparatus for providing electronically tunable biphase modulation. The apparatus includes an input for supplying a signal to be modulated and a coupler including first, second, third and fourth ports. The first port is coupled to the input. The apparatus also includes a first switch coupled to the second port. The first switch operates in response to a modulating signal. The apparatus further includes a first reactance element coupled to the first switch, an output coupled to the third port, a phase-shifting network coupled to the fourth port, a second switch coupled to the phase-shifting network and a second reactance element coupled to the second switch. The second switch operates in response to a modulating signal.

Abstract: An apparatus for providing electronically tunable biphase modulation including an input and a first switch having a first output, a second output and a first input coupled to the input. The first switch couples the first input to either the first output or to the second output in response to a modulating signal. The apparatus also includes a first signal path having a first phase shift and a second signal path having a second phase shift different than the first phase shift. The first signal path is coupled to the first output and the second signal path is coupled to the second output. The apparatus also includes a second switch having a first input coupled to the first signal path, a second input coupled to the second signal path and a terminal output.

Abstract: A microwave monolithic integrated circuit (MMIC) differential Schiffman phase shifter includes an input microstrip for receiving an input signal. First and second parallel microstrips produce a phase shifted signal from the input signal. The first microstrip is coupled at a first end to the input microstrip and at a second end to an end microstrip. The second microstrip is coupled at a first end to the end microstrip. An output microstrip is coupled to the second microstrip at a second end of the second microstrip and the input microstrip and the output microstrip are capacitively coupled. The output microstrip produces an output signal from the phase shifted signal.

Abstract: A biphase modulator without matching elements includes a Lange coupler (5) including first, second, third, and fourth ports (1,2, 3, 4), where the first port (1) receives a RF input signal. FETs (6, 7) each have a source, gate, and drain (19, 17, 18 and 22, 20, 21). The drain (18) of the first FET (6) is coupled to the second port (2), the source (19) of the first FET (6) and the second FET (7) are coupled to electrical ground, and the drain (21) of the second FET (7) is coupled to the fourth port (4). The FETs, are switched at the desired modulation frequency by a control input (16) to the gates (17, 20), alternately providing a zero volt signal and a pinch-off voltage signal which produces a biphase modulated RF input signal at the third port (3) of the Lange coupler (5).

Abstract: A semiconductor substrate with electronic circuitry (e.g., a transmitter or receiver) formed thereon and including interconnects. A ferrite disk bonded to the substrate so as to interact with the interconnects, when the ferrite disk is activated by a substantially constant magnetic field thereacross, to provide frequency selectivity within the electronic circuitry. A permanent magnet positioned adjacent to the ferrite disk to provide a substantially constant magnetic field across the ferrite disk so that the magnetic field produces resonance in the ferrite disk.

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: A lumped impedance transforming directional coupler including a first reactive element, a second reactive element coupled to the first reactive element at a first port, a third reactive element coupled to the second reactive element at a second port, a fourth reactive element coupled to the first reactive element at a third port and to the first reactive element at a fourth port, and the first, the second, the third, and the fourth ports each coupled through a first, a second, a third, and a fourth capacitor, respectively, to electrical ground, the reactive elements and the capacitors providing impedance transformation. Alternate embodiments include a lumped element directional coupler arising from a distributed impedance transforming directional couplers with a pair of transmission lines one-fourth of a wavelength of a center operating frequency in length, and a second pair of transmission lines three-fourths of that wavelength in length.