Antenna is a passive device, which mainly affects OTA power, sensitivity, coverage range and distance, while OTA is an important means to analyze and solve the throughput problem. Usually, we mainly measure the antenna according to the following parameters (the performance will also affect the throughput performance) :
a) VSWR:
Measure the degree of reflection of the input signal at the antenna feed point. This value does not mean that the antenna performance is good, but the value is not good, which meansfollowing parameters do not consider the laboratory error, the actual antenna design that the energy input to the antenna feed point at the PCBA end is reflected more, and the power that can be used to radiate has been reduced more than that of the good standing wave antenna.
b) Efficiency:
The ratio of the power radiated by the antenna to the power input to the antenna feed point will directly affect the performance of Wi-Fi OTA power (TRP) and sensitivity (TIS)
c) Gain:
It represents the power ratio between a certain position in the spatial direction and an ideal point source antenna when the input power is the same. The passive data of OTA is usually the maximum gain value of a single frequency (channel) on the sphere, which is mainly related to the transmission distance.
d) TRP/TIS:
These two comprehensive indicators are obtained by integrating and averaging the entire radiation sphere of the free space (which can be understood as the OTA laboratory environment), and can directly reflect the Wi-Fi performance of the product (OTA performance of PCBA hardware + mold + antenna).
The TRP/TIS test is much different from the expected, it is necessary to pay attention to whether the Wi-Fi enters the low power mode, and for battery powered products, it is also necessary to check whether the power is sufficient during the test; In addition, TRP needs to pay attention to ACK and non-ACK modes, and TIS has always been the focus and difficulty in OTA, after all, conduction can only reflect part of the interference situation, in addition, software factors will also have an impact on TIS.
TRP/TIS can be used as an important means of Wi-Fi throughput analysis.
e) Direction diagram:
Used to qualitatively evaluate the radiation coverage range of the product in space, its test data are usually differentiated according to frequency (channel), each frequency has H, E1, E2 three faces, thus characterizing the signal coverage of the entire sphere of the antenna. The Wi-Fi product’s wireless signal coverage is actually verified by testing the throughput at multiple angles when it is actually used over a long distance (the direction diagram cannot be represented when the distance is close).
f) Isolation degree:
The isolation degree measures the isolation degree of Wi-Fi multi-channel antennas and the mutual coupling between antennas. A good isolation degree can reduce the mutual coupling between antennas, and has a good direction diagram, so that the whole machine has a better wireless signal coverage.
The above is HDV Phoelectron Technology Ltd. brought about the “Wi-Fi antenna” knowledge explanation, and our company’s related network equipment are: OLT ONU/ AC ONU/ communication ONU/ optical fiber ONU/gpon ONU/EPON ONU and so on, welcome to understand.
