Abstract: An apparatus that includes a logarithm based processor (216) having at least one digital logarithm converter (202) and a power amplifier (208) responsive to the logarithm based processor (216).

Abstract: An apparatus for amplifying a signal that includes a digital processor (12) producing a first digital signal (20) and a second digital signal (22), a pulse width modulator (32) receiving the first digital signal (20) and producing a pulse width modulated signal, an amplitude restoration module (37) responsive to the pulse width modulator (32), the amplitude restoration module (37) producing an amplitude envelope signal, a frequency upconverter (16) receiving the second digital signal (22) and producing a frequency modulated signal, and a power amplifier (18) responsive to the frequency upconverter and the amplitude restoration module (37). The power amplifier receives the frequency modulated signal and the amplitude envelope signal and produces an amplified output signal.

Abstract: An impedance transforming power divider/combiner includes a first transmission line (60) with a first terminal (65) and N transmission line fingers (65, 66, 68, 70) terminating in N transmission line finger ends. N transmission lines (28, 38, 48, 58) having N first and second ends are positioned in close proximity to the N transmission line fingers (65, 66, 68, 70) in one-to-one correspondences. The N second ends of the N transmission lines (28, 38, 48, 58) are coupled through N individual impedances (20, 30, 40, 50) to N terminals (25, 35, 45, 55). If signal power is provided to the first terminal (64), the signal power is divided into N signal power outputs at the N terminals (25, 35, 45, 55). If signal power is provided to the N terminals (25, 35, 45, 55), a combined signal power results at the first terminal (65).

Abstract: A dielectric resonator feed back stabilizer comprising a circulator, 3-dB, 90.degree. hybrid dielectric resonator, and isolator. The circulator provides an input electromagnetic signal from a source to the hybrid, which splits the input signal into two outputs with 90.degree. relative phase difference. One hybrid output is to the load and the other is to a dielectric resonator with high Q. The dielectric resonator reflects a portion of the input signal corresponding to the dielectric resonator operating frequency back to the hybrid which splits the reflected signal into two outputs 90 degree relative phase difference. The first signal reflected back through the hybrid, 180 degrees out of phase with the hybrid input signal from the circulator, is cancelled by superposition with the hybrid input signal. The second reflected signal travels through an isolator to the circulator injection locks the source input signal.

Abstract: A miniature microstrip/cavity oscillator which is mechanically tunable over a wide range of microwave frequencies and maintains high frequency stability over changes in temperature. The oscillator consists of a RF (resonant frequency) determining element, a microstrip circuit board means, and a capacitive coupling probe coupling the microstrip circuit board means to the RF determining element. The RF determining element is constructed of various materials with different coefficients of linear expansion to eliminate expansion and contraction effects due to temperature changes.

Abstract: A pulse repetition frequency (PRF) pushing compensation circuit to negate PRF-induced frequency shifts and ambient temperature change-induced frequency shifts in pulsed RF sources. The PRF pushing compensation circuit samples PRF voltage and feeds it into a resistor-capacitor (RC) network so that the DC voltage component across the capacitor is directly proportional to the PRF. The DC voltage is then amplified, via a transistor, and fed to a varactor diode circuit coupled to the source's frequency determining element (e.g., dielectric resonator, microwave cavity, or other element). With a varactor diode tuning the source, the capacitor voltage derived from the PRF voltage is applied to the varactor diode to effect a frequency shift in the pulsed RF source which is equal and off-setting to the PRF-induced frequency shift. Temperature sensitive resistors can be used in the DC offset voltage of the varactor diode circuit to compensate for frequency changes due to ambient temperature variances.

Abstract: A microwave oscillator/power combiner incorporates two microstrip transmission lines, each coupled electromagnetically to an output transmission line. Each of the microstrip transmission lines incorporate active diodes such as IMPATT or GUNN diodes which generate RF energy when acted upon by a DC voltage. The output transmission line is coupled to ground to allow the output end of the transmission line to be adjacent to the active diodes. The two microstrip transmission lines are coupled to a high Q tank circuit through a Wilkinson power divider. The high Q tank circuit is preferably a dielectric resonator. The oscillator may be cascaded to increase power output.

Abstract: Oscillator which maintains a high Q constant frequency over changes in temperature utilizes two parallel transmission lines having an active element embedded within one of the lines. A dielectric resonator oriented one-half wave length from the embedded transmission line generates a high impedance near the embedded transmission line at resonant frequency. The resonating energy is transferred to the second parallel transmission having a low impedance. An impedance inverter matches the low impedance to the output bias and transfers the high peak powers from the low impedance in the second transmission line. The active element is bias controlled.

Abstract: Stabilizing a signal generating source by coupling a small amount of the output power through a bandpass filter tuned to the desired frequency and injecting the power back into the source. In another embodiment the filtered power may be increased by injection locking a smaller oscillator and using the output to stabilize the source, or the filtered power may be amplified in a reflection amplifier and injected into the source for stabilization.

Abstract: A ring stabilization circuit including a ring and three spaced apart arms, one of which has a dielectric resonator coupled thereto and acts to reflect, to the output arm, a resonant frequency supplied to the input arm. The impedance of the stabilization circuit is tailored to present to an oscillator an impedance value which over temperature, PRF, and other frequency changing perturbations, gives the oscillator the impedance required in order for the frequency drift to be minimized.

Abstract: A plurality of negative resistance devices is spaced below a cylindrical center conductor of a single coaxial cavity. Each negative resistance device has a bias device connected to it by a bias wire. Extending radially through the outer wall of the coaxial cavity is a coax cable with an RF coupling probe. A tuning screw is place axially through the interior of the center conductor for tuning the frequency of the power combiner.

Abstract: An improved low-cost microwave receiver is disclosed. The receiver is intended for use in the Multipoint Distribution Services (MDS) for the reception of television signals transmitted in the 2 to 2.5 GHz region. The receiver of the present invention is of the single-conversion superheterodyne type utilizing printed circuit and microstrip transmission line construction. Printed circuit board and microstrip transmission line construction permits low-cost fabrication without machined resonant cavities or waveguide components.