An apparatus utilizing the basic oscillation characteristics of the Colpitts or Pierce and Hartley oscillator configurations. In this embodiment the basic shunt reactive shunt arms are replaced with a selected pair of tank circuits or one of the shunt arms with a series-parallel tank circuit. These tank circuits are tuned such that the sign of their effective reactances are the same between the range of resonant frequencies of the individual tank circuits or of the series and parallel resonant f...

A harmonic frequency generator responsive to an input signal of frequency f hich changes slowly in both frequency and amplitude and characterized in that (1) the output signal (harmonic) amplitude remains proportional to the input signal amplitude and (2) the output frequency nf of the output signal consists soley of one integral (n>1) multiple of the input signal frequency.

A digital noise generator, wherein pseudo-random rapidly changing analog input voltages to a voltage controlled oscillator are used to generate corresponding rapidly changing discrete frequency outputs, is disclosed. Means are provided to delay the oscillator output by an amount at least equal to the rise time between each frequency change. The delayed and non-delayed oscillator outputs are electrically coupled through a switch that operates at times and at a rate to eliminate the rise time betw...

A circuit for converting a triangular waveform into a sinusoidal waveform using the non-linear transfer characteristic of a first transistor differential amplifier. Second and third differential amplifiers are parallel-connected to said first differential amplifier with the slopes of their transfer characteristics in opposite sense thereto and having their operating points shifted on their transfer characteristics in opposite directions with regard to each other and symmetrically to the operatio...

A circuit for linearizing the oscillator sweep output frequency signal of a oltage controlled oscillator is disclosed. The voltage controlled oscillator is driven by the output of an op amp, which amplifies and filters the output of a D/A converter. The D/A converter responds to preselected 8-bit words, stored in an EPROM, so as to produce a desired output frequency at each memory address. The addresses, in turn, are provided by a combination of gates, counters, input signals and a clock.

The oscillation frequency of a variable frequency oscillator is swept by a sweep signal from a sweep signal generator and the oscillation frequency is compared with a preset sweep start frequency for detecting coincidence therebetween. Upon detecting the coincidence, the sweep operation of the sweep signal generator is stopped and, at the same time, the oscillation frequency of the variable frequency oscillator is made by phase lock loop means to be phase-synchronized with a reference frequency....

A broadband high frequency signal generator is disclosed having a low and a high frequency swept signal source connected to a YIG tuned frequency multiplier. One end of an output coupling loop for the YIG is connected to ground through a PIN diode, and the low frequency signal source is connected to the junction of the output coupling loop and the PIN diode. When the PIN diode is caused to conduct, signals from the high frequency source are passed through the YIG tuned multiplier to an output in...

An apparatus suitable for use as a local oscillator is disclosed, which includes (a) a tank circuit operatively associated with an FET to generate a fundamental frequency oscillating signal at an output of the FET and (b) a bi-directional clamp circuit coupled at a junction between the tank circuit and a gate of the FET to limit a swing of the gate of the FET, preventing the gate of the FET from entering either a saturation region or a cut-off region. The bi-directional clamp includes a first di...

An improved oscillating circuit for use in microwave frequency bands has reduced power loss and is made smaller in vertical size. The local oscillating circuit includes an MMIC oscillator which comprises a FET, and a resonator connected thereto so as to stabilize the oscillating frequency of the oscillator. The resonator is ring-shaped and arranged as close as several .mu.m to several tens of .mu.m to a predetermined position of a micro strip line forming a feedback loop connected to the FET for...

A high performance oscillator with low frequency pulling at turn on includes an oscillator transistor, a resonating element and a common base buffer transistor. The resonating element of the oscillator is a circuit having a crystal resonator that is connected in parallel with a transformer winding. This resonating element is connected between the emitter of the oscillator transistor and the emitter of the buffer transistor. More specifically, a tap connects the emitter of the buffer transistor t...