White Papers

Switch-Mode RF PAs Using Chireix Outphasing

Mobile network operating costs are driving the requirement for increased infrastructure efficiency, particularly in the final stage RF power amplifier. The venerable Chireix outphasing architecture proposed in 1936 by Henry Chireix has been updated with Gallium Nitride HEMT transistors operating in class E, and shown to deliver class leading efficiency.

ROHDE & SCHWARZ

Oscilloscope Fundamentals

The oscilloscope is arguably one of the most useful tools ever created for use by electronic engineers. In the more than five decades since the modern analog oscilloscope was created, hundreds of useful documents and thousands of articles have been written about what it is, how it works, how to use it, and application-specific examples of the oscilloscope in action. It is the purpose of this primer to instead describe digital oscilloscopes, which have for practical purposes replaced their analog predecessors in the vast majority of applications.

5 RF Transmitter Measurements Every Engineer Should Know

RF transmitters are an essential part of modern communications. Designed and assembled from core RF components, RF transmitters have many different forms and applications. We often think of RF transmitters in wireless communications, but the concept applies equally to wired applications such as cable television.

Understanding VNA Calibration

In this guide, the concept of calibration is presented and discussed in detail. Specific topics to be covered include how to configure the VNA for calibration, types of calibration and calibration kits. A minimal amount of calibration mathematics and theory will also be covered.

Using RF Recording Techniques in PXI to Capture and Analyze Interference in the Signal Environment

The airwaves are becoming increasingly crowded as demand for RF spectrum continues to grow. As a result, every type of wireless communication system faces a complex and unpredictable signal environment.

Techniques for Precise Cable and Antenna Measurements in the Field

Cable and antenna measurements are often required to verify and troubleshoot the electrical performance of RF and microwave transmission systems and antennas. Measurements are often made along the coaxial cable connecting a transmitter to its antenna and/or between an antenna and its receiver.

System Noise-Figure Analysis for Modern Radio Receivers: Part 2, Y-Factor Noise-Factor Measurement

This artice is the second half of a detailed discussion of noise factor for modern RF radio receivers. In Part 1 we discussed the general concept of noise figure and how it is used to convey noise-performance requirements by product definers and circuit designers. It is also used to predict the overall sensitivity of receiver systems. We also presented calculations for a cascaded receiver. In this continuation article we focus on the Y-factor measurement as it applies to mixers. We state which measurement is applicable to the cascade equations derived in Part 1. We also explore some variations of the measurement method the could be used to obtain an approximation to the SSB noise figure of a mixer.

System Noise-Figure Analysis for Modern Radio Receivers: Part 1, Calculations for a Cascaded Receiver

This article ties together the fundamenal definition of noise figure, equation-based analysis of cascade blocks involving mixers, and typical lab techniques for measuring noise figure. In this Part 1 we show how the cascaded noise figure equation is modified by the presence of one or mixers and we derive the applicable equations for a number of popular downconversion architectures. We continue this discussion in Part 2 of this series where we describe the Y-factor method of noise-figure measurement. In Part 2 we focus on the case of a mixer as the device under test in order to identify appropriate measurement methods for mixer noise figures that can be validly applied using the cascade equations derived in Part 1.

Solutions for Design and Test of Downlink 8x8 LTE MIMO

The new application note “Solutions for Design and Test of 8x8 LTE MIMO” is designed to help you get insight into solving tough measurement problems in a unique way for both the design and manufacturing environments by explaining how to combine simulation with test solutions to realize high-performance 8x8 MIMO designs.

Resources to Optimize Your Design for Greater Battery Run-Time

Trying to increase battery life? Trying to be green or increase energy efficiency?  If so, then current consumption is most likely one of your key concerns.  Today's multi-tasking, battery-powered devices boast powerful processors, incorporate back-lit touch-screen displays, and have amassed multiple radio receivers and transmitters that are sending and receiving data at unprecedented rates.