---
title: "Microcontroller Based Four Channel RF Power Meter with Ethernet Connection for PIAVE-ALPI Cavity Accelerating Field Monitoring"
url: "https://maker.wiznet.io/praveen_k/projects/Microcontroller-Based-Four-Channel-RF-Power-Meter-with-Ethernet-Connection-for-PIAVEALPI-Cavity-Accelerating-Field-Monitoring/"
markdown_url: "https://maker.wiznet.io/praveen_k/projects/Microcontroller-Based-Four-Channel-RF-Power-Meter-with-Ethernet-Connection-for-PIAVEALPI-Cavity-Accelerating-Field-Monitoring/md"
type: "UCC: User Created Content"
author: "praveen_k"
author_url: "https://maker.wiznet.io/praveen_k/"
original_author: "praveen_k"
original_url: "https://www.lnl.infn.it/~annrep/read_ar/2010/contributions/pdfs/227_E_106_E101.pdf"
published: "2021-08-31"
language: "en"
hardware: ["ADuC7020", "WIZnet WIZ105SR", "LT5534 as RF Power Detector"]
likes: 0
views: 219
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# Microcontroller Based Four Channel RF Power Meter with Ethernet Connection for PIAVE-ALPI Cavity Accelerating Field Monitoring

> Microcontroller Based Four Channel RF Power Meter with Ethernet Connection for PIAVE-ALPI Cavity Accelerating Field Monitoring

Original author: praveen_k (source: https://www.lnl.infn.it/~annrep/read_ar/2010/contributions/pdfs/227_E_106_E101.pdf)

## Components

- **ADuC7020** x 1
- **WIZnet WIZ105SR** x 1 ([docs](https://docs.wiznet.io/Product/S2E-Module/WIZ105SR))
- **LT5534 as RF Power Detector** x 1

## Article

INTRODUCTION The actual PIAVE-ALPI RF control system does not permit the real time monitoring of the RF cavity fields when the resonators are not field locked. This information is instead precious during the cold and warm RF conditioning because it helps to optimize cavity working parameters. The knowledge of time behavior of cavity acceleration fields is also useful for radioprotection monitoring. For this reason a Four Channel Power Meter prototype, which acquires the monitor signals of 4 RF controllers and makes them available for remote acquisition has been developed and tested. Such power meter gives calibrated readings of four input channels in the range -47 to 0 dBm and actually supports Mean and Peak power evaluation over time using individual calibration curves for every channel. A similar solution can be applied to increase the accuracy of forward and reflected power readings of ALPI RF Power Amplifiers. THE CIRCUIT DESCRIPTION The three main parts of the Power Meter are ? the radiofrequency detector, microcontroller and Ethernet interface (see figure 1). For this prototype we tried Linear Technology LT5534 as RF Power Detector (see figure 2). The Analog Devices ADuC702x family showed to be the most suitable as microcontroller unit because of the wide spectrum of precise Analog Input/Output options already onboard thus eliminating the need for external circuitry. For our application we chose ADuC7020 with 5 channel 12 bit ADC converter. Interfacing to Ethernet is realized by WIZnet WIZ105SR Serial / Ethernet gateway module. It supports most of TCP/IP protocols for Serial-Ethernet communication up to 230 Kbps also including security features. Last year, for CR3 ALPI cryostat test, we made a similar device using the combination of the AD8307/AD8031 (Log Amp / Buffer) for RF Power detection and a PC with USB Card for acquiring the readings. As matter of fact the use of microcontroller gives a more compact and complete solution. For this reason we plan now to built a new prototype integrating a microcontroller and this kind of detector to compare the two power meters in terms of accuracy and sensibility before choosing the final solution for monitoring the cavity fields in ALPI. The experience acquired in the use of microcontroller can be applied for other similar projects also reusing the developed software. SYSTEM INTEGRATION The presence of microcontroller permits to choose between various measurement and communication options. For the testing purposes we implemented the 256 measurements, evenly distributed in time, for each channel. The time period and number of points can be adjusted as necessary. The mean and peak values are then calculated on this data and can be read through Ethernet TCP connection. Actually the Master PC gathers the raw data from the module applying the calibration corrections and acts as a server to give access to the users. Depending on the configuration the corrections can also be applied directly by microcontroller. Implementation of communication protocols is mostly a question of software and can be flexibly redistributed among microcontroller, gateway module, Master PC and Ethernet clients. ![](https://maker.wiznet.io/uploads/2021/08/rf-power-monitor2-300x172.png) Fig. 1. RF Power Meter layout. ![](https://maker.wiznet.io/uploads/2021/08/rf-power-monitor-300x139.png) Fig. 2. RF Power Detector Module based on Linear Technology LT5534 chip.

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Source: https://maker.wiznet.io/praveen_k/projects/Microcontroller-Based-Four-Channel-RF-Power-Meter-with-Ethernet-Connection-for-PIAVEALPI-Cavity-Accelerating-Field-Monitoring/