Abstract: A coupling arrangement for a cavity resonator (10), in particular for measuring the magnetic resonance of a sample (17) located within the cavity resonator (10) comprises a loop (14) for supplying a radio frequency signal to the cavity resonator (10) and exciting in the latter a specific mode of oscillation. For optimizing the coupling of the radio frequency signal, mechanical means are provided, preferably in the form of an axially adjustable screw (16), which permit the surface of the loop (14) to be varied mechanically, and the loop (14) is capacitively coupled with the resonator housing.

Abstract: A microwave circuit device package including a conductive housing and selectively interchangeable transmission line sections each one thereof being disposable in such housing and means for tuning and matching the impedance of the disposed transmission line section to the impedance of a device connected thereto over a relatively wide frequency band of applied signals. Such tuning means includes a conductive member of predetermined dimensions slidably mounted in proximity to a selected conductor portion of one of such transmission line sections. Such transmission line sections include a straight continuous in-line configuration for high frequencies or serpentine strip conductor configurations for low and intermediate frequencies, each one of such serpentine strip conductor configurations defining a different acute angle relative to the conductive member. The microwave circuit housing is used to test, calibrate, evaluate or characterize the properties of the connected device over the wide frequency bandwidths.

Abstract: In a microwave device, particularly a microwave local oscillator, frequency variations due to temperature changes are reduced by supporting the tuning element, for example a quartz or sapphire crystal, in the end of a tube of INVAR or other material having a low thermal coefficient of expansion. The tube projects into the cavity from a hole in one wall thereof. Preferably the tube is positively located relative to the cavity by means of an external lip on the tube abutting a shoulder formed by a reduced diameter part of the hold adjacent the cavity. The lip may be urged into positive contact with the shoulder by a spring washer acting between the end of the tube and the opposed end of a bush screwed into the hole.

Abstract: A radio-frequency matching transformer including a wave guide (W) having a fixed length. The waveguide is subdivided into sections (W.sub.1, W.sub.2) which have different characteristic impedances and the lengths of which are interdependently adjustable. A hollow cylinder is provided within the waveguide displaceable therein such that the operating frequency and the transformation ratio can be adjusted within wide ranges without a conversion of the transformer being required. This results in considerable advantages with respect to the known quarter-wave transformer.

Abstract: A cell changes conductivity by electrodeposition of a metal in response to an applied voltage pulse. The cell can be used as a variable resistance device to provide a broad frequency switching or modulating device that operates to switch dc as well as microwave energy. The cell also functions as a variable reactance device.

Abstract: 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.

Abstract: A variable impedance synthesis circuit is provided for generating a selected impedance, whether real or complex, at a predetermined port. The variable impedance synthesis circuit exhibits the selected impedance in response to control signals applied thereto.

Abstract: A suspended microstrip circuit having a dielectric substrate arranged in parallel between two parallel metal planes. First and second strip conductors are provided on the substrate, the second strip conductor being in parallel with the first strip conductor and coupled thereto. A wave phenomenon can propagate through the conductor pair in an odd mode. The metal box accommodating the microwave circuit may now be much greater so that in most cases one box is sufficient. Microwave components such as Magic-T, series-T, shunt-T, circulators, filters, attenuators, can be implemented with the suspended microstrip line.

Abstract: An antenna coupler samples the power transferred between the transmitter and the load, and at two equal distance points from the load. The coupler, based upon the value of the samples, connects a tuning stub to the transmission lines that ensures matched impedance conditions between the transmitter and the load.

Abstract: The resonator is formed with a primary line which is slightly less than a ltiple of a half wavelength long, a tee, and a matching stub. The primary line and the stub are adjustable to make the total length a multiple of one half wavelength. A mechanical link can be connected across the two adjustable lengths so as to maintain a total length of a multiple integral of one half wavelength.

Abstract: A complex RF weighter provides an RF output signal controlled in amplitude and phase with respect to an input signal. The input signal is applied to a quadrature hybrid that is terminated with two PIN diodes, one of which is one-eighth wavelength farther from the hybrid than the other. Independent control of the bias on the PIN diodes provides control of the relative amplitude and phase of the output signal.

Abstract: An impedance transformation network includes a trifilar wire configuration in which each of three conductors, each having first and second respective ends, is equally spaced with respect to one another over a predetermined length. A substantial portion of the trifilar wire is surrounded by a ferrite material. The first and second ends of a first conductor are connected to first and second connection points of a first circuit. The first end of a second conductor is connected to a first connection point of a second circuit. The second end of the second conductor is connected to a second connection point of the second circuit. The second end of the second conductor and the first end of the third conductor are connected to a third connection point of the second circuit. Where the second connection point of the first circuit and the third connection point of the second circuit are signal ground points, the network serves as a balun.

Abstract: Transformer configurations especially useful in the microwave frequency range. A reliable physical center-tap is achieved by the interposition of a stub at the center of an elongated member which provides electrical contact with a reactive impedance. The circuit formed thereby allows the reflection of an r.f. short circuit to the center of the elongated portion without attendant fabrication thereon. A loop configuration for the remaining coupling means allows adjustability of electromagnetic coupling which is less sensitive to spacing of primary and secondary than the common parallel configuration.

Abstract: The present invention relates to a class of adjustable microstrip and stripline tuners. An exemplary tuner comprises a pair of tuning elements, where each tuning element further comprises a pair of parallel spaced-apart conductive strips of equal length and at least one movable bridging wire connecting the two strips. The movement of the bridging wire will vary the output impedance of the tuning element, and a complementary arrangement of a pair of tuning elements will form a tuner capable of matching any impedance falling within the Smith chart.

Abstract: A coaxial stub tuner assembly is comprised of a short circuit branch diametrically opposite an open circuit branch. The stub of the short circuit branch is tubular, and the stub of the open circuit branch is a rod which extends through the tubular stub into the open circuit branch. The rod is threaded at least at its outer end, and the tubular stub is internally threaded to receive the threads of the rod. The open circuit branch can be easily tuned by turning the threaded rod in the tubular stub to adjust the length of the rod extending into the open circuit branch.

Abstract: The band widening circuit consists of a section of microstrip with adjustable characteristic impedance connected in series with an adjustable capacitor both connected to the three interleaved conductive pattern of the circulator. The preferred mode consists of a microstrip with air as dielectric and a conductive plate movable with respect to the conductive strip in the shape of a spiral. The capacitor is a conductive plunger movable in a conductively coated recess of a substrate for the conductive strip of the microstrip line section.

Abstract: The present invention relates to millimeter waveguide shorts and methods for making said shorts wherein an exemplary rectangular cross-sectioned waveguide short comprises a base substrate such as steel shimstock or foil having a width equal to the associated millimeter waveguide, a raised portion disposed laterally on both sides of the substrate at alternate quarter-wavelength sections adjacent one end of the substrate. The raised portions comprise a first layer of good electrically conductive material disposed on the substrate and a second layer of an insulating material formed atop the first layer. Alternatively, the exposed substrate sections can be gold plated. A preferred method comprises the steps of masking alternate quarter-wavelength sections of the exposed major surfaces adjacent one end of the substrate, depositing the first layer material on the unmasked quarter-wavelength sections and depositing the second layer material on the exposed major surfaces of the first layer material.