National Technical University of Athens
Department of Electrical and Computer Engineering
Microelectronic Circuit Design Group

Mixer Intermodulation Distortion Calculator (MIDC)

Mixer Intermodulation Distortion Calculator (MIDC) is a program that runs within Matlab's environment and is used to calculate distortion in a fully-balanced or single-ended active CMOS mixer of the Gilbert cell type. More specifically, it can compute the transconductance gain (Iout/Vin), the third-order intermodulation distortion (IM3) and the third-order input intercept point (IIP3) of the mixer.
It has the advantage over commercial SPICE-like simulators that it produces results much faster. The algorithm is based on Volterra series theory and it runs simulations in the frequency domain, instead of the time domain.

System Requirements: Matlab 7.0 or newer, Windows 2000 or XP.

If you are interested in a free copy of the program or if you have any questions please send an e-mail to midc@elab.ntua.gr.
If you would like a copy of MIDC, please, fill in this form and include it as an attachment in the e-mail.


A snapshot of the program's GUI is presented in the following picture.



Test results of MIDC compared against Cadence Spectre results for a commercial 0.18 ìm CMOS technology are depicted below.


The setup parameters for the simulations were:
RF Input Signal Frequency: 550 MHz
RF Differential Input Signal Amplitude: 20 mV
LO Signal DC Level: 1.5 V
LO Signal Frequency: 500 MHz
LO Signal Differential Amplitude: 600 mV
Switching Transistors Width: 200 ìm
Switching Transistors Length: 1 ìm
Switching Transistors Multiplier: 10
Switching Transistors Drain Voltage: 2 V
Input Transistor Width: 200 ìm
Input Transistor Length: 1 ìm
Input Transistor Multiplier: 10
Temperature: 27 C
Bias Current: 4 mA
Number of Sampling Points in a LO signal period: 200
e-mail to the Group