scieee AI-readable full text Open interactive document viewer

A mmWave RF-EMF exposure sensor for 5G FR2: Concept and Design

Jeroen Van der Straeten; Han Van Bladel; Wout Joseph; Günter Vermeeren; Luc Martens

Publisher
Zenodo
DOI
10.5281/zenodo.17435342
Repository
zenodo.org
Language
en

Abstract

Next to frequency range 1 (FR1), which covers all frequency bands situated between 410 MHz and 7125 MHz, the fifth generation telecommunication (5G) also introduced the usage of frequency range 2 (FR2). FR2 stretches from 24.25 GHz to 71.0 GHz which is quiet a jump in frequency compared to the frequencies used for legacy technologies (2G, 3G, and 4G). The introduction of this frequency range requires the need for new measurement protocols and equipment to measure radio frequency electromagnetic field (RF-EMFs) exposure induced by 5G communication at these mmWave frequencies. For FR1, several low-cost and compact RF-EMF exposure sensors already exist and are deployed in large scale RF-EMF monitoring networks. But the concept of the FR1 RF-EMF sensor cannot be replicated to achieve similar performances i.e. similar dynamic range, to monitor FR2 without "breaking the bank" – they are expensive. To realise an FR2 RF-EMF exposure sensor, a novel approach based on a mixer is proposed. Initial tests of the fundamental building blocks of the RF-EMF exposure sensor were conducted and analysed.

Full text

Goals - Focus on n258 frequency band - Flexible LO frequency - Manufacture prototypes Approach - Verify individual components - Test LO generation → generate 25 GHz signal - Test full system wired and in-situ with RF signals in the n258 frequency band Observations - PLO = 4.44 dBm meets PLO requirements of mixer i.e. 2 dBm < PLO < 6 dBm - Expected IF of fIF = 400 MHz is present when fRF = 25.4 GHz and fLO = 25.0 GHz - Unwanted intermodulation products are not present in input frequency range of the PD i.e. PD frequency range is DC – 3.9 GHz Next steps - Combine all components on a single PCB - Test power detector on IF PCB - Verify the need for extra amplification A mmWave RF-EMF exposure sensor for 5G FR2: Concept and Design PB/FB-02 Jeroen Van der Straeten*, Han Van Bladel, Wout Joseph, Günter Vermeeren, Luc Martens Department of Information Technology, Ghent University / imec, Ghent, Belgium, 9052. *Contact: [email protected] Introduction Conclusion Concept - 5G introduced the usage of the frequency range 2 (FR2; 24.25 GHz – 71 GHz). - Monitoring RF-EMF exposure due to 5G FR2 requires new monitoring equipment - Several RF-EMF exposure sensors already exist for frequency range 1 (FR1; 410MHz – 7125 MHz) Can we use the same approach for a FR2 RF-EMF exposure sensor? Frequency range Frequency band Frequency range [GHz] FR2 n257 26.50 - 29.50 n258 24.25 - 27.50 n260 37.00 - 40.00 YES, BUT… - Component options are limited, especially the power detector (PD) - Available options are expensive (e.g. HMC662) or do not meet all requirements ALTERNATIVE ? “Lower the frequency to FR1” ~ Downconverting 𝑓𝐼𝐹 = 𝑓𝑅𝐹 ± 𝑓𝐿𝑂 Broader range of components in FR1 BUT… - Higher complexity (e.g. LO generation) - Unwanted intermodulation products 𝑓𝐼𝐹 = ±𝑚𝑓𝑅𝐹 ± 𝑛𝑓𝐿𝑂, 𝑚, 𝑛 ∈ 0,1,2,… Design and results Acknowledgement This work is part of the European Union’s Horizon Europe research and innovation programme under grant agreement No 101057622 (SEAWave) and No 101057262 (GOLIAT) funded by the EU. ANTENNA 267(34)/595 LO generation - Successfully generated an LO signal that meets the LO requirements of the mixer -LO frequency is configurable via SPI Mixer - Conversion gain of mixer is 12 dB without external 90° hybrid - Intermodulation products do not interfere Successful proof of concept Antenna connected to band pass filter, low noise amplifier (LNA), power detector (PD), ADC (analog-to-digital converter), and microcontroller (µC) RF = radio frequency LO = local oscillator IF = intermediate frequency TESTED TESTCASE fRF = 25.4 GHz PRF,TX = 16 dBm dTX-RX = 2.3 m GTX = 20.4 dB