Measuring Wideband RF Signals with Power Sensors Fundamentals
The ongoing drive to transmit and receive more information wirelessly in a given bandwidth forces modern RF systems to continually increase their spectral efficiency. Some of the earliest commercial wireless systems from several decades ago utilized channel bandwidths of a just few kHz. With more and more pressure being placed on wireless systems, everything from Bluetooth headsets to aviation infrastructure to self-driving cars require wider bandwidths to achieve the required data throughput, with signal bandwidths approaching 1 GHz or more.
In aerospace/defense applications, wider RF signal bandwidths not only provide more capacity for voice and data, but their wider bandwidths also make jamming and countermeasures more difficult. One popular technique is spread spectrum, a technique in which a wide bandwidth signal is created that operates well in a noisy environment. Spread spectrum was originally adopted by the cellular industry as traditional 2G Code Division Multiple Access (IS-95 CDMA, for example) and evolved to 3G W-CDMA, with signal bandwidths approaching 5 MHz per channel.
Increasing the RF system bandwidth is one way to accommodate larger amounts of data throughput. Various modulation techniques, encoding and frequency and time division multiplexing are a few ways in which increases in spectral efficiency can be achieved. Invariably, wider bandwidths are implemented as part of an overall strategy to transmit and receive more information. Accurately measuring the power of wideband RF signals ensures efficient power usage as well as high signal quality.
How To: Measuring Pulsed RF Power
Power is a necessary parameter to measure across a wide range of modern applications and there are an assortment of instruments and methods for measuring it. Best practices, such as high-quality connectors and properly torqued components from Mini-Circuits can help minimize errors in any RF measurement. With high-performance test systems, the user should take great care to understand ways of minimizing any source of measurement error.
For measuring RF power and other pulse-modulated RF waveform characteristics, Mini-Circuits’ RF power sensors offer the convenience of modern connectivity (USB, LAN), an interactive power GUI, exceptional accuracy, and outstanding price points compared with other types of RF instrumentation.
RF Amplifier and Filter Testing with Mini-Circuits Power Sensors
RF Amplifier and Filter Testing with Mini-Circuits Power Sensors Introduction When measuring common RF components, such as filters and amplifiers, RF power sensors provide an accurate, cost-effective way to obtain meaningful data. For RF filters, parameters such as insertion loss, return loss and desired frequency response (passband and stopband) should be considered. For RF amplifiers, […]
Introduction to RF Power Measurements
Power is a necessary parameter to measure across a wide range of modern applications. Power is defined as work per unit of time. It includes units of measure such as horsepower, watts, calories per second and BTU per second, depending on the domain of interest. Electrical power is typically measured in watts, defined as one Joule per second. With RF circuits, dBm, a logarithmic representation of power level relative to the milliwatt, is often used.
An assortment of instruments and methods are used for measuring power. In this article, we will limit the discussion to electrical power, defined as voltage multiplied by current. We will further narrow the discussion to RF power, which implies higher frequency, say signals greater than 10 MHz, requiring more sophisticated instrumentation than a voltmeter due to the behavior of high-frequency electrical signals.
It is important to select the appropriate technique for measuring RF power in a given scenario. If the signal level is too high, the instrument input will become saturated; distortion, harmonics, spurious and other non-linear signals could occur. If the signal level is too low, the signal will be buried in the noise floor, making it difficult to retrieve.
A Short Primer on RF / Microwave Power Sensors
Proper power measurement techniques are important for achieving accurate results. Mini-Circuits’ PWR-series of smart power sensors now furnishes the measurement professional with the ability to make accurate peak and average measurements of CW, modulated, and pulsed RF signals at a more cost-effective price point than generally available anywhere else in the industry. Whether it’s a high dynamic range solution or a high frequency solution to 40 GHz, Mini-Circuits offers a power sensor to suit most RF/microwave engineering needs and budgets.
Mini-Circuits’ lineup of entry-level power sensor products capable of CW and true RMS measurements presents an economical option for applications requiring the measurement of CW signals to 8 GHz and modulated or multitone signals to 6 GHz. Both CW and true RMS power sensors and can be found on our main smart power sensors page.
