Rf oscillators, diode mixers, and frequency multipliers.

This section contains several types of circuit blocks for simulation with LTspice.
These include oscillators, FM oscillators (frequency modulation), frequency multipliers, and diode mixers.
Firstly you have to download and install LTspice from www.analog.com, you need this free software to open the circuits,
Then click on the names below to download the circuits and get LTspice to open the circuits
Regarding text on the circuit diagrams, blue text is just comment, black text is read by the spice simulator.
There is comment text on the circuits explaining how to run the simulation and plot the waveforms
in case of difficulty downloading, here are the circuits in this section as a ZIP file.

The circuits in this section as a ZIP file.

Colpits Oscillator circuits

Colpits oscillator, FM staircase voltage input, test.

Diode mixer circuits

The simplest ( 1 diode) mixer has the undesired characteristic that both inputs appear at the output.
you can stop the inputs from appearing at the output by using the more complex ( 2 diode, or 4 diode) mixers.
In these Diode mixer circuits, the local oscillator operates the diodes as switches, either on or off.
You can think of this on/off waveform as a square wave, this means that the local oscillator consists of its fundamental frequency and also a load of undesired harmonics at 3, 5, 7, 9 etc times the fundamental frequency, in a real circuit these extra frequencies would be filtered out.

4h single diode mixer,......... output is mixer output and both input frequencies

4jj two diode mixer,........ output is mixer output and one input frequency

4m 4 diode mixer,....... output is mixer output without either of the input frequencies

Frequency multiplier circuits

After a few circuits you may be able to ignore the directions written on the cct diagrams, as LTspice is reasonably simple to operate.