gokhansatilmis / ampdesigntool

Octave script intended for designing RF amplifiers with discrete transistors

AmpDesignTool

This Octave script is intended for designing small signal RF amplifiers with discrete transistors. The goal is to as closely as possible follow the variable names from David M. Pozars Microwave Engineering book where most of the formulas also originates from.

The script uses scattering parameters to calculate the matching network required. The script does not handle biasing but tries to give some suggested matching networks.

To preform a calculation

1. Somehow import the scattering parameters into S11, S12, S21, S22, Z0 and F. Using csv import or just enter it by hand.

2. Enter additional parameters that might be needed for the calculation. e.g. gNF, Gset, FNmin, F_, S11_ etc.

3. Choose What parameter should be the primary parameter to design for e.g. gain, bandwidth or noise. The choose the secondary parameter (see the table below).

   des_prio	Priority	Fixed	Note
   1	Gain		Maximum gain
   2	Noise>BW	Gain	Minimum noise at fixed gain
   3	Bandwidth	Gain	Maximum bandwidth at fixed gain
   4	Gain	NF	Maximum gain at fixed noise figure
   5	Bandwidth	NF	Maximum bandwidth at fixed noise figure
   6	Gain	gL	Maximum gain at fixed load impedance
   7	Noise	gL	Minimum noise at fixed load impedance
   8	Bandwidth	gL	Maximum bandwidth at fixed load impedance
   9	Gain	gS	Maximum gain at fixed source impedance

10 | Bandwidth| gS | Maximum bandwidth at fixed source impedance

4. Run the scrip to look at the result.

5. Adjust parameters accordingly.

6. Iterate step #4 and #5 until the desired design is acquired.