RF Toolbox™

powergain - Calculate power gain of 2-port network

Syntax

g = powergain(s_params, z0, zs, zl, 'Gt') g = powergain(s_params, z0, zs, 'Ga') g = powergain(s_params, z0, zl, 'Gp') g = powergain(s_params, type)

Description

g = powergain(s_params, z0, zs, zl, 'Gt') calculates the transducer power gain of a 2-port network. The input arguments are as follows:

s_params is a complex 2-by-2-by-m array, representing m 2-port S-parameters.
z0 is the reference impedance of the S-parameters. The default is 50 ohms.
zs is the source impedance. The default is 50 ohms.
zl is the load impedance. The default is 50 ohms.

g = powergain(s_params, z0, zs, 'Ga') calculates the available power gain of a 2-port network.

g = powergain(s_params, z0, zl, 'Gp') calculates the operating power gain of a 2-port network.

g = powergain(s_params, type) calculates one of two maximum gain values, determined by the type argument:

If type is 'Gmag', powergain calculates the maximum available power gain.
If type is 'Gmsg', powergain calculates the maximum stable gain.

g is a unitless power gain value. To obtain power gain in decibels, use 10*log10(g).

The specified type of power gain may be undefined for one or more of the specified S-parameter values in s_params. The powergain function returns NaN for all such values. As a result, g may be NaN or it may be a vector that contains one or more NaN entries.

Examples

The following code specifies a 2-port network, with S-parameters defined by sparam, reference impedance z0, source impedance zs, and load impedance zl.

s11 = 0.61*exp(j*165/180*pi);
s21 = 3.72*exp(j*59/180*pi);
s12 = 0.05*exp(j*42/180*pi);
s22 = 0.45*exp(j*(-48/180)*pi);
sparam = [s11 s12; s21 s22];

z0 = 50;
zs = 10 + j*20;
zl = 30 - j*40;

Perform the following calculations at the MATLAB^® prompt:

Calculate the transducer power gain of the network.

Gt = powergain(sparam, z0, zs, zl, 'Gt')

Calculate the available power gain of the network.

Ga = powergain(sparam, z0, zs, 'Ga')

Calculate the operating power gain of the network.

Gp = powergain(sparam, z0, zl, 'Gp')

Calculate the maximum available power gain of the network.

Gmag = powergain(sparam, 'Gmag')

Calculate the maximum stable power gain of the network.

Gmsg = powergain(sparam, 'Gmsg')

powergain - Calculate power gain of 2-port network

Syntax

Description

Examples

See Also