Bench Talk

New Tech Tuesday

Join journalist Tommy Cummings for a weekly look at all things interesting, new, and noteworthy for design engineers.

Who doesn't like passive components in their radio frequency circuits? Passives such as capacitors, resistors, and inductors don't complain; they go about their business keeping your RF and microwave circuits tuned.

Passives are not like their busier cousins, the active components. Actives control the flow of current. Passives do not induce any power into the circuit they are put in. They can store and dissipate energy, but they require their cousins to generate energy.

Passives might not be flashy, but they play an essential role in RF and microwave circuits. Passives include capacitors, resistors, inductors, encoders, varistors, thermistors, potentiometers, antennas, and transformers.

Design engineers use inductors and capacitors together to build filters and impedance matching circuits. In communication circuits, filtering and matching are important functions for filtering unwanted signals while maximizing the gain of desired frequencies.

This week's New Tech Tuesdays examines AVX inductors, Murata capacitors, and Vishay resistors, three new-to-market RF passives for design engineers to consider.

AVX LCCI Multi-Layer Ceramic Chip Inductors are ideal in Wireless Local Area Network (WLAN) and RF identification (RFID) systems. The inductors are also used in personal handheld systems ranging from smartphones and tablets to media players and gaming devices and electromagnetic interference (EMI) countermeasures in high-frequency circuits. And they're small: LCCI series inductors are also in the submillimeter range or tight-tolerance physical dimensions, coming in the Electronic Industries Association dimensions of 0201 (0603), 0402 (1005), and 0603 (1603). Their micro design enables compatibility with densely printed circuit boards, so get out the micro-precision tweezers. The inductors also deliver reliability and performance from 100MHz to 2.4GHz while offering 470nH maximum inductance.

Murata BBEC Silicon Capacitor is regarded as a solid performer and is prevalent in broadband applications. The BBEC series offers ultra-broadband performance up to 40GHz in a tiny package (0.6mm x 0.30mm footprint with a thickness of 100μm). This capacitor is durable and reliable when it comes to capacitance value over temperature, over-applied voltage, and aging. The insertion loss is ultra-low, and it has low equivalent series inductance (ESL) and equivalent series resistance (ESR) in bypass grounding mode.

Vishay MIB, MIF, and MIC Thin Film Microwave Resistors can be found in amplifiers, oscillators, attenuators, couplers, and filters. These resistors possess a thin resistive layer on top of a ceramic base. Chips on the alumina substrate are designed with low shunt capacitance. The resistor geometrics are compatible with strip lines, making them ideal for microwave circuits. These resistors offer a 2Ω to 20kΩ resistance range with up to ±20% tolerance in a small, single-chip package. They also come in various sizes: MIB (0201 size), MIC (0402), and MIF (02016).

Passive RF components can be small in size, but they're big in keeping the current flowing. They play a vital role in RF and microwave circuits and filter out the unwanted signals while keeping desired frequencies tuned.