hello,guys:

I am using ** ADS** the

**design guide-amplifier-DC and bias point simulation-FET_ft_fmax_vs Bias cell**to simulate the

**Fmax variance with the sweep of VGS and VDS**. when I use the original schmatic with original ideal GaAs FET, this cell works and I can get the results like below:

but when I change the FET from the ideal one to the UMS foundry HEMT, I can't get the full result(only get two) like below:

I check the error from the plot:Maximum frequency of oscillation (fmax) and other plot(shown in the above figure)

,** all the reported error** are the same as below:

While evaluating "LcsGetNewExpName1":

Operation "[ ] sweep access", index out of range in dimension 1, independent "freq" must use an index in the range 0 <= index < 0

I also check the variable fmax infomation as below:

there is a irreg which obvious not normal. and I check the help manual and get the only one matched searched result as below:

sweep_size()

Returns the sweep size of a data object

Syntax

y = sweep_size(x)

Arguments

Examples

Given 2-port S-parameters versus frequency, and given 10 frequency points, there are then ten 2 X 2 matrices. sweep_size() is used to return the sweep size of the S-parameter matrix, and its companion function size() returns the dimensions of the S-parameter matrix itself:

a = sweep_size(S) returns 10

a = size(S) returns {2, 2}

Irregular data:

Assume that the data is 3 dimensional with the last dimension being irregular. The independents are: Vsrc, size, time with dimension [3,2,irreg]. Then:

SwpSz=sweep_size(data) would return:

__SIZE SwpSz

Vsrc=1.0,size=1.0

1 20

Vsrc=1.0,size=2.0

1 21

Vsrc=2.0,size=1.0

1 59

Vsrc=2.0,size=2.0

1 61

Vsrc=3.0,size=1.0

1 76

Vsrc=3.0,size=2.0

1 78

where __SIZE is an independent added by the sweep_size() function.

sweep_size(SwpSz) would return the correct size of the two outer variables:

(1) (2) (3)

3 2 1

**as long as I tried, I can't understand what I can do to make it right....**

Can anyone knows what is going on and how to solve this?

thanks in advance!

rockyicer