scholarly journals A Method for Measuring the Maximum Measurable Gain of a Passive Intermodulation Chamber

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 770
Author(s):  
Zhanghua Cai ◽  
Yantao Zhou ◽  
Lie Liu ◽  
Francesco de Paulis ◽  
Yihong Qi ◽  
...  

This paper presents an approximate method that allows the calculation of the maximum measurable gain (MMG) in an anechoic chamber. This method is realized by using a low passive intermodulation (PIM) medium-gain directional antenna. By reducing the distance between the antenna and the wall of the chamber to reduce path loss, the purpose of replacing a high-gain antenna with a medium-gain antenna is achieved. The specific relationship between distance and equivalent gain is given in this paper. The measurement interval is determined by the 3 dB beamwidth of the measurement antenna to scan the whole chamber. A set of corresponding data for the residual PIM level and the MMG of the chamber can be obtained by the method of measurement outlined herein. The feasibility of this method was verified by measurements in two PIM measurement chambers.

2014 ◽  
Vol 716-717 ◽  
pp. 1417-1420
Author(s):  
Qun Hou ◽  
Yi Fan Zhou ◽  
Xin Peng ◽  
Long Zhang

The signal coverage technology and the difficulties of TD-LTE coverage in High-speed Train are summarized. The method of the TD-LTE uplink/downlink power budget is mentioned and the path loss and power budget are calculated in ordinary scene and tunnel scene respectively. The results show that in the F working frequency band of the TD-LTE, the maximum path loss of the High-speed Train is allowable to reach 110~130 dB. In the ordinary scene, by using large power station and a high gain antenna, the outdoor coverage radius of TD-LTE is up to 600~1000m. In the tunnel scene, using the leaked cable, the coverage radius of the RRU is up to 500m.


2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
Ivan Aldaya ◽  
Gabriel Campuzano ◽  
Gerardo Castañón ◽  
Alejandro Aragón-Zavala

Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs) have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave) frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.


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