MixIMTB_Setup (Multi-RF Intermodulation Table Extractor)
Symbol
Available in ADS
Parameters
| Name | Description | Units | Default |
|---|---|---|---|
| Filename | Name of IMT file to be generated | "imtfile.imt" | |
| RFharms[r] † † | Number of harmonics of the r-th RF input involved in mixing | None | 1, r=1 |
| RFfreq[r] † † | Fundamental frequency of r-th RF tone | Hz | 1.1 GHz, r=1 |
| RFpowr[r\] † † | Power of r-th RF tone | dBm | -50, r=1 |
| LOharms | Number of LO harmonics involved in mixing | None | 2 |
| LOfreq_Start | Nominal or lowest frequency of LO signal generated | Hz | 1.0 GHz |
| LOfreq_Stop †† | Highest frequency of LO signal generated (if swept) | Hz | |
| LOfreq_Step †† | Increment in LO signal frequency (if swept) | Hz | |
| LOpowr_Start | Nominal or lowest power of LO signal generated | dBm | -10 |
| LOpowr_Stop †† | Highest power of LO signal generated (if swept) | dBm | |
| LOpowr_Step †† | Increment in LO signal power (if swept) | dB | |
| † Add or remove elements of repeated parameters from dialog box. Ensure that identical number of harmonics, frequencies and powers are specified at all times. †† Values may be specified simultaneously in *_Stop and *_Step parameters, to sweep a corresponding variable. If both are left unspecified, only single point extraction occurs using the nominal value of the *_Start parameter | |||
Notes/Equations
- MixIMTB_Setup is an intermodulation table generating component. When linked to a three pin mixer subcircuit, it is capable of stimulating the RF and LO inputs of the mixer using multi-tone sinusoidal RF and LO signals at specified frequencies/powers, while capturing the IF output of the mixer to an intermodulation table (IMT) of specified size. It is possible to capture multiple IM tables to the same data file by sweeping LO signal powers/frequencies.
- B-type (multi-RF tone) IMT files contain double side banded complex IF voltage values (dBm,deg), in matrices sized [( 2* RFharms[1] + 1 )*..... *( 2* RFharms[r] + 1 )] x ( LOharms + 1) where RFharms various RF tones and LOharms number of harmonics participate in the mixing process. Details of file format are described in Working with Data Files > IMT Format.
- Although there is no theoretical upper limit on the number of harmonic indices that can be specified on this extractor, the user should establish a cut-off on the number of IF spurs to improve the performance of the underlying harmonic balance simulation. Using the equation for matrix size defined above, it can be verified that a simple three-tone RF input, such as used for adjacent channel power rejection (ACPR) tests, mixed at RFharm[] = {3,2,2} with LOharm = 5 will generate a 175 x 5 IMT matrix. Lowering the spur precision by 1 on each RF tone will produce a more manageable 45 x 5 IMT matrix.
- To understand the use model for this extractor see example design: BehavioralModels > MixIMT_prj > CKT_IMTA_extraction.dsn. Also see related component MixIMTA_Setup (Single-RF Intermodulation Table Extractor).
- The internal topology of MixIMTB_Setup is generated dynamically during simulation. There is no viewable sub-circuit of this component. To understand the principle of IM table generation, see how the power sources and harmonic balance controller are set up for MixIMTA_Setup (Single-RF Intermodulation Table Extractor), which is more simple.