Measurement of absorption cross section of a lossy object in reverberation chamber without the need for calibration

Abstract

Abstract-A reliable and simple procedure is proposed to measure the averaged absorption cross section (ACS) of a lossy object in a reverberation chamber (RC). This procedure is based on the time-domain measurement of the ACS in an RC. In the time-domain, to obtain the ACS, the chamber decay time needs to be known. Conventionally, the ACS is normally measured in the frequency domain, and a full two-port calibration must be carried out before collecting the S-parameters, which is tedious and time-consuming. In reality, the chamber decay time depends on the diffused loss of the RC, not the insertion loss of the cables. In this paper, by making use of this fact, the ACS can be measured accurately without calibration, which will simplify the measurement process and shorten the measurement time at the same time.

Characterization of Reverberation Chamber - A Comprehensive Review

“…The loading of the RC due to secondplaced antenna and stronger low-frequency coupling between the two placed antennas in RC for two-port S-parameter measurements are the reasons of getting relatively lower f wso using S 21 data. The findings of [50], [51] and as illustrated in Table 5 confirms that when the estimation of the wellstirred condition of the RC is required with the essential placement of the two antennas in RC as needed in [2], [7]- [10], [52], the use of the current gain transfer function of the RC environment is more appropriate. The estimated f wso using T I (jω) and |E| 24 is almost same.…”

“…S-parameters are recorded by placing a single [17] (see Fig. 1 in [17]) or two antennas in an RC [2], [8], [9], [52], [61]- [64] as illustrated in Fig. 11.…”

“…Xu et al [61] recorded the data for 10,001 linear sampling point (maximum sample point of their VNA) for the frequency range of 2.0 GHz to 2.1 GHz. Tian et al [52] used the 10,001 sample points for the frequency range of 3.8 GHz to 5.2 GHz. Table 7 presents the summary of the reviewed studies about the calculation of Q F D and Q T D .…”

Efficient Determination of Reverberation Chamber Time Constant

“…The ACS of an object in an RC can be determined from the difference in σ tot for the chamber with and without the object. From (6) the ACS of a lossy object can be written as follows [1], [11]:…”

Morphological Study on Human Body Absorption Cross Section in a Reverberation Chamber From 1 GHz to 16 GHz

“…The PDP is extracted from the inverse fast Fourier transform (IFFT) of the S 21 measured in the frequency domain, by a vector network analyzer (VNA). This method can give accurate ACS results even without the calibration of VNA [9].…”