Setup and Configuration

Location

Measurements were performed in an anechoic chamber to prevent multipath propagation. The chamber used is a fully-anechoic chamber of dimension 7 x 13.5 x 6 meter from manufacturer Frankonia. The chamber is located at the Faculty of Electrical Engineering and Information Technology of the Ruhr University Bochum, Germany. It is equipped with a rotating stage, that has a diameter of 2 meter for carrying the device under test. The rotating stage is recessed into the floor and is controlled via MatLab.

Geometries

The geometrical arrangement of the antennas and the RIS in relation to each other was investigated for 30 different scenarios. These are divided into 'specular', 'non-specular' and 'rotating stage'. For the specular reflection case, 9 geometries were evaluated, with the antennas statically positioned at -45° and 45°, respectively, and the distances to the RIS varied from 1 to 3m. For the non-specular case, 19 geometries were evaluated, with the antennas statically at 0° and 45°, respectively, and the distances to the RIS varied from 1 to 7m. For the rotating stage case, 4 geometries were evaluated, in the first three the antennas were placed statically outside the rotating stage, with the RIS rotated from -90° to 90°. In the fourth case, the transmit antenna was positioned on the rotating stage, with the receive antenna outside the rotating stage.

Each geometry is assigned a unique ID for easy identification. The IDs are broken down in a corresponding table: [Table]

Instrumentation Setup

graph LR;
    Host--USB---VNA; 
    VNA[VNA<br />PicoVNA 106]--Port 1: 15ft test cable-----TX[/TX antenna<br />A-Info LB-187-15\];
    VNA--Port 2: 15ft test cable----LNA[LNA<br />Mini-Circuits ZX60-153LN-S+]---RX[\RX antenna<br />A-Info LB-187-15/];
DC[12VDC source<br />Hameg HMP2020]---LNA;

Figure: Instrumentation setup overview

An LNA is used to overcome path loss and cable loss to optimally utilize the dynamic range of the VNA.

VNA Settings

• S21 Measurement (Amplitude+Phase)
• Start Frequency: 5.0 GHz
• Stop Frequency: 6.0 GHz
• Frequency points: 201
• RBW: 1kHz
• Port 1 power: 0 dBm

The VNA was calibrated using the corresponding PicoTech SOLT-calibration kit. The calibration plane is at the SMA male plugs interfacing the TX antenna at VNA port 1 and the LNA on port 2. Hence, the LNA gain and antenna gains are not included in the calibration, thus they are included in the provided S21 measurements.