Discone Antenna for TV Broadcasting System

Open Live Script

This example shows how to design and implement a discone antenna for indoor use in digital TV receiving and transmitting systems. Discone antennas are wide bandwidth and omnidirectional radiation antennas that are widely used in VHF and UHF broadcasting systems. The antenna consists of a circular disc and a cone whose apex approaches the centre of the disc.

Define Parameters

Rd = 55e-3;% Radius of discRc1 = 72.1e-3;% Broad Radius of coneRc2 = 1.875 e - 3;% Narrow Radius of coneHc = 160e-3;% Vertical height of coneFw = 1e-3;% Feed Widths = 1.75e-3;% Spacing between cone and disc

The above dimensions provided in [1] helps to design discone antenna to cover frequencies between 470 and 862 MHz, which is the Ultra High Frequency band of TV broadcasting.

Create Discone Antenna

Create a discone antenna using the defined parameters.

ant = discone;ant.height = hc;ant.coneradii = [rc2 rc1];ant.discradius = rd;ant.feedheight = s;ant.feedwidth = fw;数字;显示（ant）;标题（“天线元件”);

图包含一个轴对象。The axes object with title Discone Antenna Element contains 3 objects of type patch, surface. These objects represent PEC, feed.

S-Parameters

圆度天线的操作特性主要取决于宽和狭窄的半径和锥体的高度。圆盘半径和圆锥的高度与天线的最小操作频率有关，在该天线的最小直径应为天线最小工作频率的每四分之一波长为0.7倍。在此示例中，最小工作频率为470 MHz。圆盘天线的较高频率主要取决于圆锥的狭窄半径的大小以及圆锥体和圆盘之间的间隙。这些维度将控制输入阻抗，并用于保证阻抗匹配。这些尺寸的小变化可能会造成天线匹配的显着变化。

freq = (0.1:0.01:3)*1e9; [~] = mesh(ant,'MaxEdgeLength',10e-3); s1 = sparameters(ant,freq); rfplot(s1);

$图包含一个轴对象。轴对象包含一个类型行的对象。此对象表示db（s_ {11}）。$

Antenna is said to be in good performance when the reflection coefficient is below -10 dB. There is a good impedance match from 460 MHz to 2.3 GHz. When you plot the S-parameters over a wide range of frequencies, you can observe wideband characteristics of discone antenna.

Radiation Pattern

Plot radiation pattern at 470MHz

F = 470E6;数字;图案（蚂蚁，f）;

Figure contains an axes object and other objects of type uicontrol. The axes object contains 3 objects of type patch, surface.

我的模式s omnidirectional from 470 MHz to 862 MHz, with the gain ranging from 1.75 to 2.3 dBi. Due to omnidirectional characteristics, discone antenna is used in TV broadcasting systems.

Elevation Pattern

Elevation pattern is the 2D radiation pattern of the antenna.

p1 = patternElevation(ant,470e6); p2 = patternElevation(ant,862e6); p3 = patternElevation(ant,1.5e9); p4 = patternElevation(ant,3e9); figure; polarpattern(p1); hold上; polarpattern(p2); polarpattern(p3); polarpattern(p4); legend ({'470MHz'862 mhz的'1500MHz''3000MHz'});

辐射模式在方位平面中是全向的，在海拔平面中是双向的。

Conclusion

The antenna provides matched bandwidth, below -10 dB of return loss, between 460 MHz and 2.3 GHz, and provides omnidirectional radiation pattern within the considered TV band, from 470 MHz to 862 MHz. There is good agreement between the simulation results and the results from [1] in terms of directivity of radiation pattern.

参考

[1] R.Goncalves, P.Pinho and N.B.Carvalho,"Design and implementation of a 3D printed discone antenna for TV broadcasting system," 2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, Vancouver, BC, 2015, pp. 314-315.

[2] Sarita Verma, Abhilasha Mishra, Rukhsana khan, "Analysis of Variation of Various Parameters on Design of Discone Antenna", Advanced Computational Techniques in Electromagnetics, Volume 2012(2012),1-5.