User manual MATLAB RF TOOLBOX 2

[. . . ] RF ToolboxTM 2 User's Guide How to Contact The MathWorks Web Newsgroup www. mathworks. com/contact_TS. html Technical Support www. mathworks. com comp. soft-sys. matlab suggest@mathworks. com bugs@mathworks. com doc@mathworks. com service@mathworks. com info@mathworks. com Product enhancement suggestions Bug reports Documentation error reports Order status, license renewals, passcodes Sales, pricing, and general information 508-647-7000 (Phone) 508-647-7001 (Fax) The MathWorks, Inc. 3 Apple Hill Drive Natick, MA 01760-2098 For contact information about worldwide offices, see the MathWorks Web site. RF ToolboxTM User's Guide © COPYRIGHT 2004­2010 by The MathWorks, Inc. The software described in this document is furnished under a license agreement. The software may be used or copied only under the terms of the license agreement. [. . . ] It starts by converting each component network's parameters to an admittance matrix. The following figure shows a parallel connected network consisting of two 2-port networks, each represented by its admittance matrix, where Y12 Y21 Y22 Y Y [Y ] = 11 12 Y21 Y22 [ Y ] = Y 11 7-274 rfckt. parallel. AnalyzedResult property 2 The analyze method then calculates the admittance matrix for the parallel network by calculating the sum of the individual admittances. The following equation illustrates the calculations for two 2-port circuits. [Y ] = [Y ] + [Y ] = Y + Y 11 11 Y + Y 21 21 Y12 + Y12 Y22 + Y22 3 Finally, analyze converts the admittance matrix of the parallel network to S-parameters at the frequencies specified in the analyze input argument freq. The analyze method uses the parallel S-parameters to calculate the group delay values at the frequencies specified in the analyze input argument freq, as described in the analyze reference page. Examples tx1 = rfckt. txline; tx2 = rfckt. txline; plel = rfckt. parallel('Ckts', {tx1, tx2}) analyze(plel, [1e9:1e7:2e9]); plel. AnalyzedResult ans = Name: Freq: S_Parameters: GroupDelay: NF: OIP3: Z0: ZS: ZL: IntpType: 'Data object' [101x1 double] [2x2x101 double] [101x1 double] [101x1 double] [101x1 double] 50 50 50 'Linear' 7-275 rfckt. parallel. Ckts property Purpose Values Description Examples Circuit objects in network Cell Cell array containing handles to all circuit objects in the network. This property is empty by default. tx1 = rfckt. txline; tx2 = rfckt. txline; plel = rfckt. parallel; plel. Ckts = {tx1, tx2}; plel. Ckts ans = [1x1 rfckt. txline] [1x1 rfckt. txline] 7-276 rfckt. parallel. Name property Purpose Values Description Examples Object name 'Parallel Connected Network' Read-only string that contains the name of the object. plel = rfckt. parallel; plel. Name ans = Parallel Connected Network 7-277 rfckt. parallel. nPort property Purpose Values Description Examples Number of ports 2 A read-only integer that indicates the object has two ports. plel = rfckt. parallel; plel. nPort ans = 2 7-278 rfckt. parallelplate. AnalyzedResult property Purpose Values Description Computed S-parameters, noise figure, OIP3, and group delay values rfdata. data object Handle to an rfdata. data object that contains the S-parameters, noise figure, OIP3, and group delay values computed over the specified frequency range using the analyze method. The analyze method treats the parallel-plate line as a 2-port linear network and models the line as a transmission line with optional stubs. The analyze method computes the AnalyzedResult property of the line using the data stored in the rfckt. parallelplate object properties as follows: · If you model the transmission line as a stubless line, the analyze method first calculates the ABCD-parameters at each frequency contained in the modeling frequencies vector. It then uses the abcd2s function to convert the ABCD-parameters to S-parameters. The analyze method calculates the ABCD-parameters using the physical length of the transmission line, d, and the complex propagation constant, k, using the following equations: A= B= C= D= ekd + e- kd 2 Z0 * ekd - e- kd 2 e kd ( ) -e 2 * Z0 - kd ekd + e- kd 2 Z0 and k are vectors whose elements correspond to the elements of f, the vector of frequencies specified in the analyze input argument 7-279 rfckt. parallelplate. AnalyzedResult property freq. Both can be expressed in terms of the resistance (R), inductance (L), conductance (G), and capacitance (C) per unit length (meters) as follows: Z0 = R + j 2fL G + j 2fC k = kr + jki = ( R + j 2fL)(G + j 2FC) where R= 2 w cond cond d w w d L= G = C= w d In these equations: - w is the plate width. is the imaginary part of , = 0rtan , where: · · · 0 is the permittivity of free space. tan is the LossTangent property value. 7-280 rfckt. parallelplate. AnalyzedResult property - cond is the skin depth of the conductor, which the block calculates as 1 / f cond . f is a vector of modeling frequencies determined by the Output Port block. · If you model the transmission line as a shunt or series stub, the analyze method first calculates the ABCD-parameters at the specified frequencies. It then uses the abcd2s function to convert the ABCD-parameters to S-parameters. When you set the StubMode property to 'Shunt', the 2-port network consists of a stub transmission line that you can terminate with either a short circuit or an open circuit as shown in the following figure. Zin is the input impedance of the shunt circuit. The ABCD-parameters for the shunt stub are calculated as: A =1 B=0 C = 1 / Zin D =1 When you set the StubMode property to 'Series', the 2-port network consists of a series transmission line that you can terminate with either a short circuit or an open circuit as shown in the following figure. 7-281 rfckt. parallelplate. AnalyzedResult property Zin is the input impedance of the series circuit. The ABCD-parameters for the series stub are calculated as: A =1 B = Zin C=0 D =1 The analyze method uses the S-parameters to calculate the group delay values at the frequencies specified in the analyze input argument freq, as described in the analyze reference page. Examples tx1 = rfckt. parallelplate; analyze(tx1, [1e9, 2e9, 3e9]); tx1. AnalyzedResult ans = Name: 'Data object' Freq: [3x1 double] S_Parameters: [2x2x3 double] GroupDelay: [3x1 double] NF: [3x1 double] OIP3: [3x1 double] Z0: 50 ZS: 50 ZL: 50 IntpType: 'Linear' 7-282 rfckt. parallelplate. EpsilonR property Purpose Values Description Examples Relative permittivity of dielectric Scalar The ratio of the permittivity of the dielectric, , to the permittivity of free space, 0. The default value is 2. 3. tx1=rfckt. parallelplate; tx1. EpsilonR=2. 7; 7-283 rfckt. parallelplate. LineLength property Purpose Values Description Examples Parallel-plate line length Scalar The physical length of the parallel-plate transmission line in meters. The default is 0. 01. tx1 = rfckt. parallelplate; tx1. LineLength = 0. 001; 7-284 rfckt. parallelplate. LossTangent property Purpose Values Description Examples Tangent of loss angle Scalar The loss angle tangent of the dielectric. The default is 0. tx1=rfckt. parallelplate; tx1. LossTangent=0. 002; 7-285 rfckt. parallelplate. MuR property Purpose Values Description Examples Relative permeability of dielectric Scalar The ratio of the permeability of the dielectric, , to the permeability of free space, 0. Change the relative permeability of the dielectric: tx1=rfckt. parallelplate; tx1. MuR=0. 8; 7-286 rfckt. parallelplate. Name property Purpose Values Description Examples Object name 'Parallel-Plate Transmission Line' Read-only string that contains the name of the object. tx1 = rfckt. parallelplate; tx1. Name ans = Parallel-Plate Transmission Line 7-287 rfckt. parallelplate. Separation property Purpose Values Description Examples Distance between plates Scalar Thickness, in meters, of the dielectric separating the plates. The default is 1. 0e-3. . tx1=rfckt. parallelplate; tx1. Separation=0. 8e-3; 7-288 rfckt. parallelplate. SigmaCond property Purpose Values Description Examples Conductor conductivity Scalar Conductivity, in Siemens per meter (S/m), of the conductor. [. . . ] The units of the frequency point must be specified explicitly using the abbreviations GHz, MHz, kHz, or Hz. This example of a second line indicates that the section contains input power data that is assumed to be in decibels referenced to one milliwatt, unless other units are specified. It also indicates that the power data was measured at a frequency of 2. 1E+009 Hz. PIN dBm FREQ=2. 1E+009Hz Data The data that follows the header typically consists of three columns: · The first column contains input power data. · The second column contains the corresponding output power magnitude. [. . . ]