---
title: "Microcontroller Based Four Channel RF Power Meter with Ethernet Connection for PIAVE-ALPI Cavity Acc"
url: "https://maker.wiznet.io/WIZnet/projects/microcontroller-based-four-channel-rf-power-meter-with-ethernet-connection-for-piave-alpi-cavity-acc/"
markdown_url: "https://maker.wiznet.io/WIZnet/projects/microcontroller-based-four-channel-rf-power-meter-with-ethernet-connection-for-piave-alpi-cavity-acc/md"
type: "UCC: User Created Content"
author: "S. Stark, A.M. Porcellato, F. Chiurlotto, R. Ponch"
author_url: "https://www1.lnl.infn.it/~annrep/read_ar/2010/contributions/pdfs/227_E_106_E101.pdf"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "S. Stark, A.M. Porcellato, F. Chiurlotto, R. Ponch"
original_url: "https://www1.lnl.infn.it/~annrep/read_ar/2010/contributions/pdfs/227_E_106_E101.pdf"
published: "2023-02-21"
language: "en"
hardware: ["WIZnet WIZ105SR"]
likes: 2
views: 418
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

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

> a Four Channel Power Meter prototype, which acquires the monitor signals of 4 RF controllers and makes them available for remote acquisition

Original author: S. Stark, A.M. Porcellato, F. Chiurlotto, R. Ponch (source: https://www1.lnl.infn.it/~annrep/read_ar/2010/contributions/pdfs/227_E_106_E101.pdf)

## Components

- **WIZnet WIZ105SR** x 1 ([docs](https://docs.wiznet.io/Product/S2E-Module/WIZ105SR))

## Article

**DETAILS**

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.

---

Source: https://maker.wiznet.io/WIZnet/projects/microcontroller-based-four-channel-rf-power-meter-with-ethernet-connection-for-piave-alpi-cavity-acc/