Abstract:
A broad-band cavity-tuned transistor oscillator includes a field effect device having capacitive feedback from source to drain and having a gate capacitively coupled to a cavity for producing an output signal that is frequency selectable according to cavity resonance, which resonance is determined by translation position of a mechanical tuning plunger coupled to the cavity and the degree of capacitive feedback.
Abstract:
Disclosed is microwave oscillator or amplifier circuitry which is tunable over a wide bandwidth and which includes an improved variable loading on a negative resistance semiconductor diode, such as an IMPATT diode. This loading is provided in mutually perpendicular directions closely adjacent the diode. In one direction, a DC bias connection is mounted together with an adjustable coaxial filter thereon, and this filter serves as a series tuning element for the diode. A movable short is mounted for adjustment in a direction perpendicular to that of the above coaxial filter and provides parallel tuning for the diode. These series and parallel tuning elements are operative to match the real and imaginary components of the diode impedance to the real and imaginary components of the load impedance, respectively, at a particular operating frequency, thereby maximizing the power transfer and the DC to RF conversion efficiency of the circuitry. For ease of frequency adjustment, all of the frequency dependent parameters of the circuitry are contained in a removable and replaceable insert which fits securely into the waveguide housing.
Abstract:
This relates to a broadband injection-tuned Gunn diode microwave oscillator module. The module includes a Gunn diode and a microwave resonant cavity. The resonant cavity is a multi-tuned circuit to present the Gunn diode with its negative impedance over the requisite frequency band. The cavity is an evanescent mode waveguide. Tuning is accomplished solely by an injection locking signal which modifies the impedance of the cavity to match the Gunn diode over the requisite frequency band. This type of tuning eliminates the need for either electronic tuning of the Gunn diode and/or mechanical tuning of the cavity.
Abstract:
A microwave oscillator which is intended for a semiconductor element and which is accommodated in a ridge-type waveguide. The waveguide is formed on the one side by a portion of small height which is closed by a short-circuit element, and on the other side by a portion having a progressively increasing height which is provided with a resonant structure. The resonant structure is formed by a thin vertical pin and by two further pins which are arranged perpendicular to the side walls of the wave guide and which can be axially adjusted. The assembly formed by these three components constitutes a transmission line which enables transmission of a microwave according to the T.E.M.-mode.
Abstract:
A four-diode bridge is positioned within the cavity of a Gunn diode oscillator. A subharmonic signal is applied to the diode bridge and the diode bridge couples an odd harmonic of the injected signal into the cavity. The cavity is thus caused to resonate at the odd harmonic of the injected signal. The injected signal can be changed using a frequency synthesizer in order to provide a microwave oscillator with multiple-channel operation. The diode bridge provides a feedback signal indicative of the phase of cavity oscillation. The feedback signal is applied to a varactor which pretunes the Gunn diode oscillator and thereby provides phase-locked control.
Abstract:
A microwave frequency oscillator utilizing a push-push configuration to provide a low noise highly stable output signal at twice the frequency of a single resonator. The single resonator is connected in the feedback loop of two amplifiers. Additional circuit elements insure the proper oscillation conditions and relative phase are maintained. The use of a single resonator makes possible the application of various noise reduction techniques.
Abstract:
An integrated circuit tunable cavity oscillator for extremely high freque operation in image line waveguide. The oscillator includes a metal base with a cylindrical bore, a dielectric or semiconductor waveguide mounted atop the metal base and having a bore which is continuous with the metal base bore. A Gunn or IMPATT diode is assembled in the metal base bore on top of a drum which is urged upwards toward the waveguide bore by a spring located behind the drum. From above, cavity tuning means including a top disk and a threaded screw cover the waveguide bore and push the diode into the metal base bore to define the cavity height of the coaxial cavity of the oscillator. The waveform, which is set up in the recessed cavity in the metal base, is launched into the waveguide. Thus, a ruggedized, low cost, tunable (by a tuning screw) and low weight oscillator for millimeter wave image line or microstrip operation is obtained. Furthermore, the oscillator diode and cavity defining hardware are easily replaceable.
Abstract:
A low cost arrangement for a millimeter wave solid state diode oscillator,hich obviates precise machining and uses a dielectric transmission line associated with a resonant cavity. Coupling and impedance matching are greatly facilitated by a conductive stripe structure on the end of the dielectric transmission line, extending into the resonant cavity of the solid state oscillator. Fine tuning is provided by a mechanical slide screw. Two layers of shielding surrounding the resonant cavity are provided by a convenient package suitable for various applications of the millimeter wave oscillator wherein leakage radiation is not permitted.