Abstract: A double balanced mixer for mixing an RF input signal with a local oscillator signal to provide at an output an intermediate frequency signal with high isolation over a wide frequency range. The mixer includes a local oscillator balun that is operable to receive a local oscillator signal. A RF balun that is operable to receive a RF signal. A first mixer has a first input port that is coupled to the local oscillator balun and a second input port that is coupled to the RF balun. The first mixer has an output port to provide an intermediate frequency signal. A second mixer is coupled in parallel with the first mixer. The second mixer has a first input port that is coupled to the local oscillator balun and a second input port that is coupled to the RF balun. The second mixer has an output port that provides an intermediate frequency signal. An intermediate frequency balun is coupled to the output ports of the first and second mixers.

Abstract: A miniature wideband RF choke has a low temperature co-fired ceramic substrate with a top surface and a bottom surface. A first inductor is located within the substrate. Terminals are located on the top and bottom surfaces. A second inductor is located on the top surface. The second inductor has a core wound with a wire. Vias extend through the substrate connecting the terminals to the inductors.

Abstract: A power splitter has a small size with good electrical performance. The power splitter includes a substrate with several dielectric layers. A capacitor is formed between two of the dielectric layers. A pair of inductors are formed by circuit lines located on the dielectric layers. Several terminals are located on outer surfaces of the substrate. Conductive vias extend between the layers in order to provide an electrical connection between the capacitor, the inductors and the terminals. The substrate is formed from layers of low temperature co-fired ceramic. The circuit lines have a curving or sinuous shape on the dielectric layers. The inductors are electromagnetically coupled. The power splitter has a compact overall size.

Abstract: A three way power splitter that has a small package size. The three way power splitter includes a multi-layered low temperature co-fired ceramic substrate. An input transformer and three output transformers are attached to the top of the substrate. The transformers have wires that are attached to terminals on the top of the substrate. Three resistors are located on the top surface of the substrate under the transformers. A capacitor is located within the substrate. Terminals are also located on the bottom of the substrate. Several conductive vias extend through the substrate and connect the resistors, the capacitor and the terminals.

Abstract: A low cost power splitter that has a small size and can be used with automated surface mount manufacturing equipment. The power splitter includes a case having a cavity and a lead mounting surface. Leads are secured to the lead mounting surface. A substrate is mounted in the cavity. The substrate has top surface, a bottom surface and inner layers. A resistor is formed on the top surface. A capacitor is formed on the inner layers. Terminals are located on the top surface and vias extend through the substrate. A pair of transformers are attached to the bottom surface and to the case by an adhesive. The transformers have windings that are connected to the terminals. Connector wires are connected between the terminals and the leads.

Abstract: A power splitter that has a small package size and repeatable electrical characteristics. The power splitter includes a low temperature co-fired ceramic (LTCC) substrate with several layers. Electrical components such as resistors and capacitors are integrated within the LTCC substrate. A transformer is attached to the upper surface of the LTCC substrate and is electrically connected to the resistors and capacitors. The transformer provides impedance matching and dividing functions. The LTCC substrate has electrically conductive vias extending therethrough. The vias are used to connect the power splitter to an external printed circuit board. The vias are also used to make electrical connections between the layers of the LTCC substrate.

Abstract: A wide bandwidth mixer has a low temperature co-fired ceramic substrate. The substrate has a top layer, a bottom layer and inner layers. Vias extend through the substrate. A local oscillator balun and an RF balun are located on the inner layers and connected to the vias. An intermediate frequency balun is mounted to the top layer and connected to the vias. Field effect transistors are mounted on the top layer and connected to the local oscillator balun, the RF balun and the intermediate frequency balun through the vias. A matching network is mounted to the top layer and is connected to the vias. The matching network matches the impedance of the field effect transistors to that at the LO port.

Abstract: A double balanced FET mixer that has a high third order intercept point and an intermediate frequency response that goes to direct current levels. The mixer includes a local oscillator terminal, a RF terminal and an intermediate frequency terminal. The mixer has a pair of field effect transistors. Each field effect transistor has a gate, a drain and a source electrode. The source electrodes of the first and second transistors are connected together. A first balun transformer is connected between the local oscillator terminal and the gates. A second balun transformer is connected between the drains and the RF terminal and the intermediate frequency terminal.

Abstract: A mixer with improved isolation between the RF and local oscillator frequency signals. The mixer has a substrate. A pair of cores are mounted to the substrate. Windings are wound on the cores to from a pair of baluns. A diode ring is connected between the baluns. The windings are formed from a first and second twisted pair of wires on one core and a third and fourth twisted pair of wires on another core. Some of the wires are wound on the cores but not twisted together. This winding configuration achieves superior balance between the baluns and good isolation.

Abstract: A protection circuit for Darlington amplifiers prevents destructive voltage overshoot conditions from occurring. The Darlington amplifier has a pair of transistors connected in a Darlington configuration. A biasing network is coupled to the transistors for supplying a bias voltage to the transistors. A pair of de-coupling capacitors is coupled to the transistors. One of the de-coupling capacitors is coupled to the input of the Darlington amplifier and the other is coupled to the output. The output capacitor has a larger capacitance than the input capacitor such that excessive voltage is prevented from developing on the transistors.

Abstract: A filter for filtering electronic signals that has improved isolation. The filter has a multi-layered dielectric block that has six surfaces. The block has a center portion. An input terminal is located on one side surface and has a portion extending onto the adjacent side surfaces toward the center portion. An output terminal is located on another side surface and has a portion extending onto the adjacent side surfaces toward the center portion. A pair of ground terminals are located on two other side surfaces at the center portion. A partial ground plane is located within the dielectric block. The ground plane extends from the center portion toward but not to the input and output terminal portions. The partial ground plane improves isolation of the filter.

Abstract: A triple balanced mixer has a compact size and is readily assembled. The triple balanced mixer has a planar substrate that is formed from several layers of low temperature co-fired ceramic. The substrate has a top layer, a bottom layer and inner layers. Vias extend through the substrate. A local oscillator balun and RF balun are located on the inner layers. An intermediate frequency balun is mounted to the top layer. Diode rings are mounted on the top layer. The diode rings are electrically connected to the local oscillator balun, the RF balun and the intermediate frequency balun through the vias.

Abstract: A test apparatus and method of measuring pulling of the frequency of an oscillator. The apparatus includes a bias tee, a power supply, a spectrum analyzer, a second power supply, a symmetrical resistive power splitter, a power meter and a synthesized signal generator. The method includes sweeping the synthesized signal generator frequency from the nominal frequency down to a first frequency. The first frequency is recorded when the oscillator goes out of frequency lock as a first pulling frequency. The synthesized signal generator frequency is then sweet from the nominal frequency up to a second frequency and the second pulling frequency is recorded when the oscillator goes out of frequency lock. The difference between the first and second pulling frequencies is the peak to peak pulling value.

Abstract: A roof panel clip that extends ten feet in length rather than the usual prior art one to two inches, enabling the clip to span the distance between two purlins to support roof panels over these distances. The extended length of the clip enables it to provide greater strength against uplift loads than that which was possible with the older narrower clips and this continuous clip can be installed more quickly than a series of the ususal smaller clips used to cover the same span.