AC2001

Millimeter Wave gunn Oscillator Module

Dynex Semiconductor has developed a low cost, state of

the art Millimetre Wave Gunn diode based oscillator

module that operates in the 75 to 80 GHz band, with a 1

GHz operational bandwidth.

The initial application of the oscillator is within an

automotive product.

The use of Gunn technology provides performance

advantages compared to competing technologies.

Figure 1 Millimeter Wave Gunn Oscillator Module

Features

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High output power

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Low phase noise performance

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Frequency stability with temperature

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Frequency agility

DS5074-3.0 January 2000

Applications

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A low noise source for research use

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Autonomous Intelligent Cruise Control systems

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FMCW and Doppler radar systems

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Voltage controlled oscillator

The Gunn diode is a custom MBE grown GaAs

hetrojunction device incorporated into a machined alloy

body with an integral custom waveguide 26 flange. The

oscillator is a radial mode 2nd harmonic bias tuned

design.

For microstrip applications a waveguide to 0.18mm

microstrip step transition is available to interface the

oscillator to microstrip circuits.

A separate power supply driver PCB can be provided to

interface to the Gunn module. This provides over voltage,

spike and reverse polarity protection. The driver PCB

also allows ease of frequency setting or the application of

modulation.

It should be noted that the Gunn diode is easily damaged

by voltage transients or reverse bias. It is recommended

that the driver circuitry is always used to protect the Gunn

diode from potential damage.

It is possible to extend the lower operational temperature

range of the oscillator by applying a small DC voltage to

the oscillator. This voltage is insufficient to generate any

RF power.

The required frequency range must be specified when

ordering the parts.

Specification

Potential operating frequency range

75 - 80 GHz

Microwave Output power (@25

∞C)

+16 dBm min.

SSB Phase Noise (100kHz offset)

-85 dBc/Hz typ.

Operating voltage range

5.0 - 6.5 V

Supply current

750 mA typ.

DP/DT (max.)

0.35 mW/

•C

DF/DT (typ.)

1 - 2 MHz/

•C

Voltage pushing

400 - 800 MHz/V

Operational temperature range

-30

∞C to +85 ∞C

Weight (Oscillator only)

25 g approx.

Frequency adjustment or modulation of the oscillator is

achieved by changing the oscillator bias supply via the

driver PCB. The driver PCB provides a control voltage

input for this purpose. The voltage limits must be within

those specified

Replaces March 1999, version DS5074-2.0