# AD633 and frequency mixer circuit with dual gate mosfet

#### mos_6502

Joined Dec 11, 2017
37
In order to find the difference between the frequencies of two signals, I'm using an AD633.

This works well, but it is very expensive.

The AD633 is a "simple" frequency mixer?
Is it possible to realize the same circuit using components as double gate mosfets that are easy to find? (the circuit should not use inductors)

#### OBW0549

Joined Mar 2, 2015
3,566
In order to find the difference between the frequencies of two signals, I'm using an AD633.

This works well, but it is very expensive.

The AD633 is a "simple" frequency mixer?
Is it possible to realize the same circuit using components as double gate mosfets that are easy to find? (the circuit should not use inductors)
The AD633 is an analog 4-quadrant multiplier IC. According to the data sheet, it has a 1 MHz bandwidth and handles signals up to ±10V.

The range of possible solutions for a "simple" frequency mixer to find the difference in frequency of two signals depends greatly on the amplitude of your signals, and their frequency. What works at 500 Hz will not necessarily work at 500 MHz, and vice versa. Likewise, what works at 10 volts may not work at 10 mV, and vice versa.

What are the voltages of your two signals? What are their approximate frequencies?

#### mos_6502

Joined Dec 11, 2017
37
In my project, I have a local oscillator with a sinewave between 5Vpp and 3.3Vpp. The signal "RF" have amplitude from 3.3Vpp to 10-20mVpp.

The frequency for my actual project are from 30KHz to 2MHz.

No one has an answer?

Last edited by a moderator:

#### Bordodynov

Joined May 20, 2015
2,906
You should reduce the input signal by 10 times. After that you can use the mixer (multiplier) circuit on a two-gate transistor. Apply the signal to the lower gate, and apply the local oscillator voltage to the upper gate. Do a search in Google.

#### mos_6502

Joined Dec 11, 2017
37

If I wrote in this forum is because I have not found anything concrete looking with google!

#### bertus

Joined Apr 5, 2008
21,532

#### crutschow

Joined Mar 14, 2008
27,712
The old MC1496 modulator/demodulator (Gilbert multiplier) IC should also do what you want.
It generally sells for less than a dollar US.

#### mos_6502

Joined Dec 11, 2017
37
Hello,

Can't you find a ciruit?
This query will give you about 500.000 results:
"dual gate mosfet mixer"

Bertus
I have certainly not looked at all the results (Yahoo and Google), but the first two pages reported generic circuit (without real components), schematics with obsolete components or circuits with inductors.

Search engines do not offer much in specific cases like this. For this reason I am writing on this forum.