淘宝官方店推荐课程在线工具联系方式关于我们

	微波射频仿真设计 Ansoft Designer 中文培训教程 \| HFSS视频培训教程套装
	Agilent ADS 视频培训教程 \| CST微波工作室视频教程 \| AWR Microwave Office

首页 >> Ansoft Designer >> Ansoft Designer在线帮助文档

Ansoft Designer / Ansys Designer 在线帮助文档：

Transmission Line Designer >
Transmission Lines >
Suspended Substrate Transmission Line

Suspended Substrate Transmission Line

Keyword	Default	Unit	Description
W	Req (Phys)	m	Conductor width
P	0	m	Physical length of transmission line
Z0	Req (Elec)	ohm	Transmission line impedance
E	0	deg	Electrical length of transmission line
Frequency	100 MHz	Hz	Analysis frequency
ER	Req		Relative dielectric constant
H	Req	m	Substrate thickness
HL	Req	m	Distance between bottom of substrate and ground
HU	Req	m	Cover height above substrate
A	inf.	m	Width between sidewalls
TAND	0		Dielectric loss tangent
RGH	0	m	Rms surface roughness

Synthesis and Analysis

• To synthesize suspended substrate transmission lines, the parameters Z0, H, HU, HL, A and ER must be entered prior to clicking the Synthesis button. The width, W, will be computed.

• For analysis, the parameters W, H, HL, HU and ER must be entered prior to clicking the Analysis button. The A parameter is assumed to be infinity. The impedance, Z0, will be computed. The frequency will be used if entered; otherwise, 100 MHz will be used in the calculation.

• Conversion from electrical length, E, to physical length, P, can be performed by entering values for E and Frequency. Click Synthesis to compute P. Similarly, to convert from physical length to electrical length, enter values for P and Frequency, and click Analysis to compute E.

Dielectric Substrates

A dielectric substrate is defined by the parameters H, ER, and TAND. The substrate is assumed to be lossless unless TAND is specified and greater than zero.

Conductor Metallization

• Conductor specification is performed in the Metallization control group. If the conductor is not specified, the conductor loss is zero and no thickness corrections are made to the structure’s propagation characteristics. Up to three conductors of different metals and thicknesses can be specified.

• Metallization rms surface roughness, RGH, can be specified for additional conductor losses due to imperfect metal surfaces. RGH is specified in terms of rms variation from an ideal flat surface.

Sweep Options

Parameters that can be swept for the suspended substrate transmission line are:

Frequency
Width, W

The order shown is the order used to generate output data when multiple parameters are swept simultaneously. Refer to the Sweep Entries section for further information.

Limitations

Full-wave analysis is used; there are no limitations for practical dimensions.

Example

To select the suspended substrate medium, select TRL on the Product menu, click Stripline, and click Single. Set the units to mm and GHz. We will use the following parameters for synthesizing a 50-ohm transmission line:

Impedance, Z0: 50 ohms

Frequency: 10 GHz

Substrate thickness, H: 0.635mm

Lower height, HL: 1.0 mm

Upper height, HU: 1.0 mm

Sidewall width, A: 10.0 mm

Dielectric constant, ER: 9.8

Dielectric loss, TAND: 0.001

Metal: Cu 0.01 mm

Click the Synthesis button to determine the line’s parameters:

Width, W: 1.79 mm

Keff: 2.25

Note that the impedance has changed slightly to 49.6 ohms. This is due to the synthesis being approximate for this medium

To specify a 1/4 wavelength line, enter:

Electrical length, E: 90

Click Synthesis again to determine the corresponding physical length:

Physical length, P: 5.0 mm

The dispersion of the medium can be observed by sweeping frequency. Sweep from 0 to 30 GHz in steps of 2 GHz by typing 0.1,30,2 in the Frequency field.

Single Line in Suspended Substrate Stripline

H = 0.635mm ER = 9.80 TAND = 0.00100 T/H = 0.0157

Freq Width W/H Z0 Keff C loss D Loss T Loss

ghz mm Ohms dB/mm dB/mm dB/mm

0.1 1.786 2.812 55.95 2.081 0.0002 0.0000 0.0002

2.1 1.786 2.812 55.63 2.088 0.0009 0.0001 0.0010

4.1 1.786 2.812 54.76 2.108 0.0013 0.0002 0.0015

6.1 1.786 2.812 53.41 2.142 0.0016 0.0004 0.0019

8.1 1.786 2.812 51.64 2.189 0.0019 0.0005 0.0024

10.1 1.786 2.812 49.54 2.251 0.0022 0.0007 0.0029

12.1 1.786 2.812 47.16 2.328 0.0025 0.0010 0.0034

14.1 1.786 2.812 44.58 2.422 0.0028 0.0013 0.0041