Rockwell International Corporation

Ben R Hallford

Robert W McKenzie

Bruce C Lutz

Karl R Varian

The present inventive concept combines two signals, each representative of a portion of a single signal, wherein the two signals have different non-linear slopes, and produces a single linearly changing output signal indicative of the combination. This circuit is specifically used in combination with the feedback loop of a delayed automatic gain control circuit to detect the signal level applied to the gain control circuit and to provide a linearly changing output signal representative of the decibel value of the signal applied to the automatic gain control circuit. This is accomplished by linearizing the two different signals independently, and establishing a maximum value for one signal, a minimum value for the other signal, and summing these in conjunction with a reference to produce a single composite linearly changing signal.

Dual signal amplitude modifying and combining apparatus

A drop-in module in an RF frequency amplifier circuit is illustrated having space feedback between the gate and drain terminals, and having a unique mounting technique for electrically connecting the source terminals to the ground plane on the opposite side of the substrate portion of the drop-in module. The electrical connection is accomplished by using a U-shaped piece of strap metal, which is inserted in two slots with the legs or tabs of the U-shaped strap metal being bent over to be soldered to the source leads, while the bit portion of the U-shaped member is soldered to the ground plane on the opposite side of the substrate. This allows easy attachment and removal of the FET to the exposed electric circuitry, while still maintaining a definable and appropriate low impedance electrical path from the source leads to the ground plane.

Microwave plug-in signal amplifying module solderment apparatus

Space feedback comprising a shield over the tuning elements of a FET radio frequency amplifier provides positive feedback between the gate and drain terminals to raise the gain of the amplifier above what it would be without the space feedback, while simultaneously lowering the noise figure. Not only is the relative noise lowered, but the absolute amount of noise is lowered.

Space feedback apparatus for field effect transistors

A unitary component operating as a low noise amplifier incorporates several other tuning components in conjunction with an FET. By adjusting the tuning components, the overall amplification and impedance characteristics of the unit can be standardized in spite of typical variations in impedance and amplifying characteristics of the FET by itself. The incorporation of such a drop-in module in a microwave circuit, simplifies testing and repair of the remaining portions of the circuit, since the drop-in modules can easily be tested and adjusted for proper operation in a test jig separate from the actual operating circuit.

Microwave plug-in signal amplifying module

A variable transformer is illustrated to be used primarily with high frequency transistors and other high frequency amplifying means to provide optimum impedance matching characteristics for individual transistors in a circuit rather than trying to design a given circuit to be universally applicable to a range of transistor characteristic values.

Transistor amplifier variable matching transformer apparatus

Microstrip transistor characteristic matching apparatus is illustrated which can be altered as to design frequency, phase of reflection signal coefficient and magnitude of reflection coefficient to optimize signal transmission to or from a given transistor. After adjustment, the apparatus can be analyzed to quickly determine the characteristics required for an in-circuit commercial version of such a device.

Universal transistor characteristic matching apparatus

Microwave circuit layout structure is disclosed for a diode mixer frequency converter. Each mixer port is provided by balun circuitry, and the diodes are isolated from, and on the opposite side of the substrate from, the primary circuits of the baluns. Single and double sideband versions are disclosed, including various combinations of dual and single baluns and porting structure.

Full balun mixer

Microwave circuit layout structure is disclosed for a diode mixer bridge. The circuit layout structure is compact and symmetric, and enables short orthogonal equal length leads from a diode ring quad mixer bridge. The configuration also affords equal path lengths through the diodes to provide precise 180.degree. phase differential image frequency cancellation. The structure also affords precise and consistent mounting of the mixer bridge, to further improve performance.

Symmetric microwave mixer

Microwave circuit layout structure is disclosed for a diode mixer frequency converter. The circuit layout structure is compact and symmetric, and enables coplanar diode lead connection.

Symmetric microwave mixer with coplanar diode connection

Microwave circuit layout structure is disclosed for a diode quad mixer frequency converter with separate, isolated sections, each supplied by a respective half of dual balun port structure. The circuit layout structure is compact and symmetric, and enables coplanar diode connection.

Symmetric microwave mixer with improved isolation

A low frequency diode mixer is provided in combination with simple, compact transformer circuitry. A four diode mixer interconnects three dual transformers. The mixer has a pair of separate, isolated two diode sections commonly servicing the first transformer and separately servicing the other two transformers.

Low frequency converter with isolated mixer sections

A microwave frequency converter is provided with a diode mixer bridge having a balanced port connected to a dual balun. The dual balun is provided by two pairs of balanced secondary conductors juxtaposed a common primary conductor, each pair contributing to the field between balanced conductors leading to the mixer bridge. The dual balun and microstrip circuit layout enable a wider gap to be used between the balanced conductors to the bridge, which enables manufacturably cost efficient implementation.

Microwave frequency converter with dual balun port

A microwave frequency converter is provided with cost effectively manufacturable microstrip layout circuitry, particularly for directionally coupling the LO signal. A pair of unbalanced microstrip conductors lead from a mixer bridge respectively to a pair of balun IF rejection filters juxtaposed on the opposite side of a dielectric substrate. A second pair of unbalanced microstrip conductors lead respectively from the pair of balun IF rejection filters to a microstrip branch line coupler.

Microwave frequency converter with economical coupling

A low frequency, diode quad mixer is provided in combination with simple, compact transformer circuitry. A diode quad mixer bridge interconnects the secondary winding of a single transformer and the four secondary windings of a pair of dual transformers. The combination affords isolation between the signals coupled through each of the transformers, and may be implemented as an up converter or a down converter.

Low frequency converter with diode quad mixer

A low frequency, diode pair mixer is provided in combination with simple, compact transformer circuitry. A diode mixer bridge has a pair of diodes interconnecting secondary windings of single and dual transformers. The diodes are connected in series across the secondary winding of the single transformer. The same polarity ends of the pair of secondary windings of the dual transformer are connected in common to a point between the diodes. The other ends of the pair of secondary windings are connected to respective ends of the secondary winding of the single transformer. The combination affords isolation between the signals coupled through each of the transformers. The combination may be implemented as an up converter or a down converter.

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Wylie, TX, United States of America

Ben R Hallford