A New Method for Antenna Efficiency Measurements

天线效率测量的新方法

• 批准号: EP/G062501/1
• 负责人: Yi Huang
• 金额: $ 15.34万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG062501%2F1
• 关键词: New; Method; Antenna; Efficiency; Measurements

The antenna, as an essential device for radio systems, has a number of important parameters to characterise its performance. One of them is the antenna radiation efficiency (i.e. antenna efficiency) which is the ratio of the radiated power to the input power. This parameter is very useful to calculate the radiated power once the input power is known. Since the theoretical value for this parameter is normally not reliable due to the complexity of the antenna system (including materials), measured antenna efficiency is often required for system design (link budget) and performance evaluation. The traditional methods to obtain this parameter are 1). radiation pattern integration method which is time consuming and not accurate; 2). Wheeler cap method which is accurate and cheap but only suitable for electrically small antennas; 3). the Q factor method which is also just suitable for electrically small antennas. The 1st method was normally used when the operating frequency is relatively high while the other two methods were employed when the operating frequency is relatively low. More recently the reverberation chamber was attempted as a new facility for measuring the antenna efficiency, but this method requires a reference antenna with a known efficiency and the accuracy is yet to be proven. As the trend of radio systems moves towards broader bandwidth and higher frequencies, the traditional methods are no longer adequate, for example, the Wheeler cap method cannot be employed to measure UWB antennas due to the ultra-wide bandwidth nature. There is an urgent need for a better method which can be used to measure these new antennas efficiently and accurately. This project consists of both theoretical and experimental work and is aimed at developing a new antenna efficiency measurement method which is based on the Wheeler cap idea, i.e. utilising a conducting cavity. However, this cavity does not need to be electrically small and the resonant modes inside the cavity can be as many as that in a reverberation chamber (which can be viewed as an over mode cavity with rotating stirrers). In the new method, the antenna under test (AUT) is placed inside the cavity at a number of strategic positions to remove the effects of the resonance and the complex reflection coefficient S11 of the antenna is measured. The antenna efficiency can then be obtained using these measured S11. A calibration and data interpretation software are required. Unlike any existing methods, the loss of the cavity, which could be significant in some cases, will be taken into account. Thus the proposed method should be more accurate than current methods and it should also be cheap and convenient as the Wheeler cap method. Furthermore, It will be suitable for various antennas over a large range of frequency. Thus this innovative method can be used to measure small and large, narrow and wide band antennas, meet the demand from the industry and provide an alternative method to the measurement and wireless community.

天线作为无线电系统的重要设备，具有许多重要参数来表征其性能。其中之一是天线辐射效率（即天线效率），它是辐射功率与输入功率的比率。一旦已知输入功率，该参数对于计算辐射功率非常有用。由于由于天线系统的复杂性（包括材料），因此该参数的理论值通常不可靠，因此系统设计（链接预算）和性能评估通常需要测得的天线效率。获得此参数的传统方法为1）。辐射模式集成方法，既耗时又不准确； 2）。 Wheeler Cap方法准确且便宜，但仅适用于电气小天线； 3）。 Q因子方法也仅适用于电气小天线。当工作频率相对较高时，而在工作频率相对较低时，使用了第一个方法。最近，试图将混响室作为测量天线效率的新设施，但是该方法需要具有已知效率的参考天线，并且准确性尚未得到证明。随着无线电系统的趋势朝着更广泛的带宽和更高的频率发展，例如，由于超宽的带宽性质，传统方法不再足够，因此无法使用Wheeler Cap方法来测量UWB天线。迫切需要一种更好的方法，该方法可用于有效，准确地测量这些新天线。该项目既由理论和实验工作组成，旨在开发一种基于Wheeler Cap Idea的新天线效率测量方法，即使用导电腔。但是，该腔不需要电气小，并且腔内的谐振模式可以与混响室中的谐振模式（可以看作是带有旋转搅拌器的超模式腔）。在新方法中，将正在测试的天线（AUT）放置在许多战略位置内，以消除共振的效果，并测量天线的复杂反射系数S11。然后可以使用这些测得的S11获得天线效率。需要校准和数据解释软件。与任何现有方法不同，在某些情况下可能会有重要的腔体损失。因此，所提出的方法应比当前方法更准确，并且作为Wheeler Cap方法，它也应便宜且方便。此外，它适用于各种频率的各种天线。因此，这种创新的方法可用于测量大小，狭窄和宽带天线，满足行业的需求，并为测量和无线社区提供另一种方法。

项目成果

Wideband antenna efficiency measurements

• DOI: 10.1109/iwat.2010.5464803
• 发表时间: 2010-03
• 期刊: 2010 International Workshop on Antenna Technology (iWAT)
• 作者: Y. Huang;Y. Lu;S. Boyes;H. Chattha;N. Khiabani

Measurement and Performance of Textile Antenna Efficiency on a Human Body in a Reverberation Chamber

• DOI: 10.1109/tap.2012.2225817
• 发表时间: 2013-02-01
• 期刊: IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
• 影响因子: 5.7
• 作者: Boyes, Stephen J.;Soh, Ping Jack;Khiabani, Neda
• 通讯作者: Khiabani, Neda

Two Alternative Methods to Measure the Radiated Emission in a Reverberation Chamber

• DOI: 10.1155/2016/5291072
• 发表时间: 2016-02
• 期刊: International Journal of Antennas and Propagation
• 影响因子: 1.5
• 作者: Qian Xu;Yi Huang;S. Yuan;Lei Xing;Z. Tian

Source-stirred method for antenna efficiency measurements

用于天线效率测量的源搅拌方法

• 发表时间: 2011
• 期刊: EuCAP 2011
• 作者: Huang Y

Anechoic and Reverberation Chambers: Theory, Design, and Measurements

消声室和混响室：理论、设计和测量

• 发表时间: 2018
• 作者: Xu Qian