• 首页
• HFSS教程
• ADS教程
• CST教程
• 射频工程师培训
• 微波仪器操作培训
• 天线设计培训
• 射频专业基础课

Ansoft Designer / Ansys Designer 在线帮助文档：

Nexxim Simulator >
Nexxim Component Models >
Controlled Sources >
   Voltage-Controlled Current Source, LaPlace       

Voltage-Controlled Current Source, LaPlace

VCCS LaPlace Netlist Format

The voltage-controlled current source with LaPlace transfer function uses two different formats, the coefficient format and the pole zero format.

Coefficient Format

In the coefficient format, H(s) is specified by giving the coefficients of the transfer function polynomials:

Gxxxx out+ out- LAPLACE in+ in- a0[,] ... aN / b0[,] ...bD

[SCALE=val] [TC1=val] [TC2=val] [M=val]

out+ is the positive node and out- is the negative node of the current source. The entry LAPLACE selects the G element LaPlace transfer function type. in+ and in- are the positive and negative nodes for the control voltage. The division symbol (/) in the instance line is required syntax.

The function of the device is expressed as:

I(out+, out-) = SCALE ´ H(s) ´ V(in+, in-)

The transfer function H(s) is the ratio of two polynomials in the complex variable s.

The coefficients (a₀ ... a_N) specify the numerator polynomial of the ratio. The coefficients (b₀ ... b_D) specify the denominator polynomial. The subscripts N and D represent the order of the numerator and denominator respectively. The first coefficients in both numerator and denominator (a₀ and b₀) are constants, which must be specified even if they are zero. Thus, leading zeros are significant. In addition, intermediate zero-valued coefficients must be explicitly supplied in order to have the non-zero coefficients applied to the correct powers of s. Trailing zeros are not significant, and are automatically removed.

For example, to specify the following transfer function (where coefficient a₁=0):

A coefficient format netlist would contain the following statement:

Gex1 out gnd LAPLACE in gnd 1, 0, 2 / 1, 1, 3

Pole Zero Format

The pole zero format specifies the complex roots of the transfer function polynomials:

Gxxxx out+ out- LAPLACE in+ in-
rz1 iz1 ... rzN izN / rp1 ip1 ... rpD ipD
POLE [SCALE=val] [TC1=val] [TC2=val] [M=val]

The pole zero syntax must include the keyword POLE. The slash (/) is required. The nodes and other parameters are the same as for the coefficient format.

The parameters rz₁ iz₁... rz_N iz_N in the numerator are the complex zeros of the transfer function. The parameters rp₁ ip₁... rp_D ip_D in the denominator are the complex poles of the transfer function.

Both poles and zeros are complex numbers with a real part and an imaginary part. Each root must specify the magnitudes of both real and imaginary parts even if one of them is zero (j, the square root of -1, does not need to be entered). The list must also provide the complex conjugate of each root when the magnitude of the imaginary part is nonzero. The roots may be entered in any order.

For example, to specify zeros of s-1, s-2j with complex conjugate s-(-2j), s-(-1+3j) with complex conjugate s-(-1-3j), the denominator entry would be:

1 0 0 2 0 -2 -1 3 -1 -3

VCCS LaPlace Element Netlist Examples

G21 21 0 LAPLACE 31 0 0.1 2.2 -.3 / 0.25 -2.1 0.33 -.4

G14 33 0 LAPLACE 44 0 .4 0 .35 -.2 .35 .2 / 1.0 2.5 1.0 -2.5
+ .56 0 1.8 0 POLE

                HFSS视频教程                                      ADS视频教程                               CST视频教程                           Ansoft Designer 中文教程

      Copyright © 2006 - 2013   微波EDA网, All Rights Reserved    业务联系：mweda@163.com