I. Introduction
II. Theoretical Methods
1. Electromagnetic Topology
2. Power Balance Method
III. Measurement and Simulation
1. Measurement Set-Ups
The first measurement method (Step 1) was performed as shown in Fig. 4(a). In the case of this measurement method, it was performed to check and record the level of the referenced received power. An absorber was installed at the bottom between the transmitter and receiver to measure the line-of-sight (LoS) signal strength.
The second measurement method (Step 2) was to maintain the same transmit/receive system and position, as in the first case, and install the shield room and a stirrer as shown in Fig. 4(b). The stirrer was used to control the condition of the environment inside the shield room in which the measurement was performed in accordance with the PWB method. During this measurement, the stirrer rotates at a constant speed, and the receiving antenna is installed facing the transmitting antenna. If the stirrer works properly, the EM waves propagated into the shield room are uniformly distributed in the shield room. The receiving system measures 20 samples per frequency and stores them in the computer.