Herzlich Willkommen beim beam-Verlag in Marburg, dem Fachverlag für anspruchsvolle Elektronik-Literatur.


Wir freuen uns, Sie auf unserem ePaper-Kiosk begrüßen zu können.

Aufrufe
vor 7 Jahren

10-2016

  • Text
  • Komponenten
  • Technik
  • Radio
  • Filter
  • Oszillatoren
  • Quarze
  • Emv
  • Messtechnik
  • Bauelemente
  • Software
  • Frequency
  • Wireless
  • Antenna
  • Anwendungen
  • Antenne
  • Frequenzbereich
  • Circuit
Fachzeitschrift für Hochfrequenz- und Mikrowellentechnik

RF & Wireless Test &

RF & Wireless Test & Measurement USB Pulse Power Sensors AR RF/Microwave Instrumentation once again sets the standard with the introduction of its fast RF power measuring PSP series wideband USB pulse power sensors. contrast, the detector on the right has sufficient video bandwidth in order to track the envelope accurately. It is possible for the detector to track very fast amplitude changes due to modulation, by optimizing the sensor’s response time. The video bandwidth of the sensor must be at least as wide as the signal’s modulation bandwidth in order to be able to accurately track it. The PSP001 provides an industry leading video bandwidth of 195 MHz for spread-spectrum signals, and measures rise times as fast as 3 ns. It has a sample rate of 100 MHz enabling the analysis of both very short bursts and very broadband signals, as well as power versus time waveforms in very high resolution. Real Time Power Processing (RTPP) is a new signal processing technology which is a key factor in ensuring the accuracy of measurements. This advanced technique enables the sensors to constantly collect samples without any gaps in their acquisition, ensuring that no USB Pulse Power Sensors Application Note #73 ARRF/microwave Instrumentation www.arworld.us Built with Real-Time Power Processing technology, this new product line offers high speed and accuracy that customers demand. AR’s USB pulse power sensors are ideal for EMC testing, manufacturing testing/troubleshooting, amplifier design/development, and research. These devices can be used in both commercial and military applications such as telecommunications (LTE-TDD/ FDD), avionics, RADAR, and medical systems. They are the instrument of choice for fast, accurate and highly reliable RF and microwave power measurements. This application note will discuss some of the key features and benefits of AR’s new line of PSP Series Wideband USB pulse power sensors as shown below. How Does It Work? The USB Pulse Power Sensor functions as an ultra-fast, calibrated power measurement tool which acquires and computes the instantaneous, average and peak RF power of a wideband modulated RF signal. An internal A/D converter operates at up to 100 MSamples/s, and a digital signal processor carries out the work required to form the digital samples into a correctly scaled and calibrated trace on the display. The first and most critical component of a peak power sensor is the detector, which removes the RF carrier signal and outputs the amplitude of the modulating signal. The video detector’s bandwidth dictates the sensor’s ability to track the power envelope of the RF signal. The picture on the left in Figure 2 below shows how a detector with insufficient bandwidth is unable to faithfully track the signal’s envelope, therefore affecting the accuracy of the power measurement. In *RTPP-Real Time Power Processing Figure 1: Block diagram of the peak power sensor 60 hf-praxis 10/2016

RF & Wireless Figure 2: The Importance of Detector Bandwidth data is lost. The conventional method involves collecting samples until the sensor’s buffer is full, at which point acquisition stops until the collected samples are processed. RTPP collects and processes samples so quickly that the buffer is never filled. In order to create a trace on the screen, conventional meters and USB sensors carry out the required steps in sequence, which therefore means that processing can take as long as tens or hundreds of milliseconds. Real Time Power Processing performs many of these steps in parallel and at full acquisition rate, so it is not necessary to halt acquisition following a trigger event to wait for the processing stages to catch up. Measurement of Amplifier compression using AR’s PSP Series Wideband USB Pulse power sensors and PulsewARe: Figure 3 shows an example of AR’s PSP series demo set-up, where we make readings similar to a scalar analyzer to measure gain of an RF power amplifier. The PSP Series pulse power sensors are supported by both AR’s emcware software and PulsewARe. PulsewARe is a Windows-based software package that provides control and readout of the sensors as shown in Figure 4. It provides both time and statistical domain views of power waveforms with variable peak hold and persistence views. Power measurements are supported using automated pulse and statistical measurements, power level and timing markers. The GUI application is easily configured with dockable or floating windows and measurement tables that can be edited to show only the measurements of interest. With statistical analysis capability the PSP series can display the statistical distribution of the signal power level relative to its average power in a format called complementary cumulative dis- Table 1: PSP Series Wideband USB pulse power sensors and key features hf-praxis 10/2016 61

hf-praxis

PC & Industrie

© beam-Verlag Dipl.-Ing. Reinhard Birchel