[time-nuts] Looking for 1 GHz low phase noise amplifier

[Garry Thorp]

Mini-Circuits' GALI- series of InGaP MMICs work pretty well. They typically have ~4dB NF, and the noise performance seems to be maintained up to a couple of dB below 1dB compression.

I haven't measured added phase noise, but absolute phase noise measurements, where the MMICs are used to amplify multiplied-up crystal oscillators, appear to indicate added noise less than -180dBc/Hz at 10kHz offset when scaled to 120MHz (using 20log(N) relationship).

The GALI- series are traditional MMICs that require a resistor or current source to bias them. We have had problems with Some TriQuint InGaP MMICs that are designed for voltage biasing. Noise from their internal bias circuitry seems to get on to the signal, and the NF started to increase well below compression. Mini-Circuits' GVA- series may well be similar, as they are also voltage-biased.

Garry Thorp


Date: Fri, 27 Sep 2013 10:53:10 -0700

From: Richard Karlquist richard at karlquist.com<mailto:richard at karlquist.com>

Can anyone suggest a low phase noise amplifier covering

something like 10-1000 MHz? Gain should be 10 to 20 dB

and phase noise should be spec'ed at +10 to +13 dBm output.

Both close in and far out phase noise are of interest.

Thanks in advance.

Rick Karlquist