Abstract: A microwave frequency doubler circuit, which includes a full wave rectifier for rectifying an input signal and to provide two outputs, and a differential amplifier having inputs connected to the two outputs.

Abstract: An APC (automatic phase control) circuit is utilized to measure the linearity of an FMO (frequency modulated oscillator). In accordance with a common APC concept a programmable divider is connected to an output of said frequency modulatable oscillator to produce a binary output signal having a predetermined pulse repetition rate. This signal is compared with a reference oscillator signal in a phase control comparator producing a DC control signal which is applied to the control input of said frequency modulated oscillator to maintain the average oscillator frequency constant. This DC control voltage gives an indication of average free running frequency of the oscillator.To measure linearity, the said binary signal at the programmable divider output is also further divided and processed to produce a low frequency square waveform which is applied via a manual ON/OFF switch and a modulation amplifier to the modulation input of the said FMO.

Abstract: In a microstrip frequency modulated oscillator, the linearity of the modulating circuit incorporating a varactor diode is adjusted by using a microstrip transmission line as a secondary resonator in conjuction with a variable reactor. The varactor is connected to one end of this resonator which end is also connected to the main resonator of the microstrip oscillator. The variable reactor is connected between the other end of the secondary resonator and ground.

Abstract: A novel technique for coupling microwave signals to a slot transmission line and for effecting a simultaneous impedance transformation. One lead of a microwave capacitor, connects to a source of microwave signals via a microstrip or coplanar transmission line. The other capacitor lead, located in the same plane as the slot line, crosses the slot line at a right angle and connects to the ground plane on the other side of the slot. A short-circuited segment of the slot line extends N.lambda./4 beyond the point of crossing where N is an odd integer.

Abstract: A microwave signal generator having improved noise spectral characteristics employs a plurality of amplifier-frequency multiplier circuits in combination with a very stable VHF oscillator. Instead of lumping the amplification and frequency multiplication together, each in a single stage, a plurality of amplifiers and multipliers are interleaved, as described herein, resulting in reduced FM noise generation.