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The use of the Wiener–Khinchin theorem in the reverberation chamber reveals the relationships between a number of important parameters—the coherence bandwidth and the Q-factor measured in the time domain, the coherence time and the Q-factor measured in the frequency domain, the K-factor and the Doppler spectrum, and the K-factor and the total scattering cross section. The lower bound of the average K-factor is also given. Different physical quantities, which share similar mathematical insights, are unified. Analytical derivations are given, and results are validated by measurements. [ABSTRACT FROM AUTHOR]

Measuring the shielding effectiveness (SE) of physically small but electrically large enclosures is an important concern in electronics industry. In recent years, reverberation chambers (RCs) are becoming prevalent in determining the SE of such enclosures. Conventionally, frequency-domain (FD) measurement is adopted. It requires three antennas (one transmitting antenna and one receiving antenna in the large RC and one receiving antenna in the nested small enclosure). Furthermore, to obtain good accuracy, the knowledge of the efficiency of the two receiving antennas is also required. To promote the industrial application of RCs for SE measurement, simplified methods are desired. In this paper, simplified measurement methods are proposed and studied both in the FD and the time domain (TD). Only two antennas are required in the proposed methods. Thus, the measurement setup is greatly simplified. It is found that in the TD, a fast and accurate measurement method can be realized with the simplified measurement setup. Moreover, the measurement simplification can go a step further by replacing the RC with an electrically large metallic enclosure in the TD. The measurement results demonstrate that the TD approach outperforms the FD approach in many ways. The proposed methods have the merits of high efficiency, good accuracy, and simple measurement setups. They are very suitable for SE measurement of electrically large enclosures. [ABSTRACT FROM PUBLISHER]

The averaged absorption cross section of a lossy object can be measured in a reverberation chamber (RC). Conventionally, the measurement is conducted in the frequency domain and it requires two antennas with known efficiency. In this paper, the two one-antenna methods are presented—one is in the frequency domain and the other is in the time domain. In the frequency domain, by using the enhanced backscatter effect, the measurement setup is greatly simplified and only one antenna with known efficiency is required. In the time domain, the measurement can be conducted rapidly and accurately using just one antenna and the source stir technique by considering the robustness of the chamber decay time; moreover, the RC can be replaced by a suitable electrically large conducting cavity, which will greatly reduce the hardware requirement. It is found that the time-domain approach is superior to the frequency-domain approach in many aspects. The new measurement methods are efficient and accurate, while the system requirements and setup are simpler than the conventional ones. [ABSTRACT FROM AUTHOR]

In this paper, the B-scan technique is applied to a reverberation chamber (RC) for the first time to characterize the time-domain behavior of the chamber. Based on B-scan measurement results, three things are studied in this paper. 1) The statistical behavior of the fields in the time domain is investigated, and it is found that the received power of the impulse response follows chi-square distribution with one degree of freedom. 2) The stirrer efficiency is quantified based on the equivalent total scattering cross section (TSCS) of stirrers, and this definition is not sensitive to the antenna position and load in the RC. It is shown that the stirrer efficiency defined in this paper provides, for the first time, a quantitative way to evaluate the stirrer design and the chamber performance. 3) A time-gating technique is proposed which provides an alternative method to eliminate the early time response and obtain the chamber transfer function of the RC accurately. This could be potentially used to increase the stirrer efficiency without changing the stirrers physically. It is demonstrated that the B-scan technique is a very useful approach for the study and evaluation of an RC. [ABSTRACT FROM PUBLISHER]

A new method is proposed to measure the shielding effectiveness (SE) of an electrically large enclosure. Traditionally, the SE measurement requires at least two (in an anechoic chamber) or three antennas (in a reverberation chamber). In this paper, only one antenna is needed in the whole measurement procedure. There is no requirement to use a reference antenna. It is interesting to note that if the aperture of the enclosure under test (EUT) can be covered (by using a conductive sheet or aluminum foil), the SE can be measured quickly by comparing the Q factor or the decay time of the covered and uncovered EUT. Measurements have been conducted to evaluate and verify the proposed method. The results are compared with those obtained using the nested reverberation chamber method; limitations of the proposed method are also discussed and identified. It is found that when the EUT is well shielded, the uncertainty of the proposed method could be relatively large. Nevertheless, the proposed method does offer a new simple and efficient approach to measure the SE of an electrically large enclosure. [ABSTRACT FROM AUTHOR]