Complementary Cumulative Distribution Function (CCDF) in Modern Modulation Measurements
Mar 03, 2026 | Power Sensors
As utilization of wireless communications hs accelerated over the past few years, the push to make efficient use of the limited amount of spectrum available has led to the development of more complex modulation schemes. Waveforms continue to evolve for constant-envelope GSM and IS-95 CDMA of yesteryear to QAM and OFDM

How Loops and Probes Couple to Cavity Filters
Feb 16, 2026 | Filters
Cavity filters are ubiquitous today, and they are not new to the world of RF and microwave engineering. Cavity filters have been around for almost 80 years, since Fano and Lawson completed their initial work in 1948.2,3 They are widely used in RF and microwave systems where high selectivity, low insertion loss, and excellent power handling are required. They are commonly found in SATCOM, radar, EW, ECM, and even test and measurement systems. One critical aspect of cavity filter design is how energy is coupled into and out of the resonant structure. Among the various techniques available, coupling loops and coupling probes (henceforth, more commonly “loops” and probes”) are the two most common methods. Each method relies on a different electromagnetic coupling mechanism and offers distinct advantages depending on frequency, power level, bandwidth, and mechanical constraints.