Frequently Asked Questions

What does Virginia Diodes do?
What is a millimeter-wave?
What is a diode?
Do I need a VDI diode?
What is a frequency multiplier?
Why should I use a VDI frequency multiplier?
What is a mixer?
Why should I use a VDI mixer?

What does Virginia Diodes do?
VDI designs and manufactures millimeter-wave diodes, integrated components and systems operating from 18 GHz to over 3 THz. Our products are widely used in radio astronomy, millimeter-wave spectroscopy, compact radar, atmospheric physics, plasma diagnostics and a wide range of other scientific instrumentation. Our products are based on a proprietary GaAs Schottky diode technology that enables them to operate at frequencies well beyond the standard commercial microwave and millimeter-wave bands.

What is a millimeter-wave?
The term millimeter-wave typically refers to a portion of the electromagnetic spectrum where the wavelength is in the range from 10 mm to 1 mm (30 GHz to 300 GHz). However, millimeter-wave may be loosely applied to include the portion of the electromagnetic spectrum with wavelengths from 10 mm to 0.1 mm (30 GHz to 3 THz). The millimeter-wave spectrum lies between the microwave and infrared as indicated in the graphic below.

What is a diode?
A diode is a two terminal electronic device that allows electrical current to flow in one direction but blocks current flow in the other direction. Harmonics are generated due to the non-linearity of the voltage and current.

Do I need a VDI diode?
If your application requires a diode operating at frequencies above 100 GHz, then the answer is probably yes. If your application is below 18 GHz then the answer is probably no.

What is a frequency multiplier?
A frequency multiplier converts energy from a signal source to a higher frequency. This is particularly usefull at very high frequencies where it is more difficult to generate fundamental oscillations.

Why should I use a VDI frequency multiplier?
VDI's frequency multipliers operate at room temperature (no need for a cryogenic dewar), provide large fixed-tuned bandwidth (no mechanical tuners) and provide state-of-the-art power and conversion efficiency.

What is a mixer?
A mixer converts energy from a signal source to a lower frequency where it can be amplified and processed more easily.

Why should I use a VDI mixer?
VDI's mixers are extremely sensitive and have very low noise. Our mixers operate at room temperature, so you don't need a cryogenic dewar. Our mixers are very broadband, typically covering a full standard waveguide band (~ 40 %). And finally, our mixers do not employ any type of mechanical tuners, so they may be electronically swept to any frequency within their operating band.