High- frequency diodes

High-frequency diodes serve as detector (demodulator) diodes, mixing diodes or modulator diodes.

1. The detector diodes are used to separate a low-frequency informative signal from high-frequency modulated oscillations.

2. The mixing diodes are used to change carrier frequency of modulated oscillations.

3. At last, the modulator diodes are used to modulate an informative signal by high-frequency oscillations.

In order to extend the diode frequency range, it is necessary to decrease the diode capacitance.

The so-called point-contact construction ensures with low capacitance in diodes. It permits to increase operating frequency of diodes up to 300-600MHz. The inductance of holders in those diodes is very low, but reverse voltage does not exceed 3-5V. Point-contact diodes are in wide use as non-linear elements for high-frequency signal detection and frequency conversion.