Apart from HB-QPSS of Cadence Spectre,
I've been feeling that HB-PSS of Cadence Spectre come to be enough practical level if no NPORT is included in target circuit.
But HB Analysis of Cadence Spectre is very slow when NPORT is included even if there is only one.
This is true for both convolution and rational fitting model.
I tried both tstab=0 and tstab!=0, but no improvement.
When I use HB Analysis of Cadence Spectre,
I often encounter no convergence even if there is only one NPORT in circuit.
Especially if I use large inductor such as 18nH for 2.4GHz operation frequency from the following library,
HB analysis of Cadence Spectre can't converge at all even if it is only one NPORT in circuit.
http://www.murata.co.jp/cgi-spara/search.pl?primary=lqg15hn&lang=en http://www.murata.co.jp/cgi-spara/search.pl?primary=grm15&lang=enExtraporation for high frequency might cause this convergence failure
since provided maximum frequency data is lower for larger inductor.
At least if I endure very slowness of Cadence Spectre,
I can barely get convergence when I use two or three NPORT of not so large inductor at most in circuit.
But I've never been able to get convergence of HB Analysis in Cadence Spectre when I use more than four NPORT.
When I use HB Analysis of Agilent GoldenGate,
I can get always convergence very quickly without any problem even if there are more than ten NPORT in circuit.
Is there anyone who can get convergence even if more than four NPORT are used in HB Analysis of Cadence Spectre ?
Do you have any trouble when NPORT is used in HB Analysis of Cadence Spectre ?