Active Band Switching Solutions Written By: Alessandro Beretta Abstract: Today’s new and emerging wireless applications are increasingly requiring the support of multiple frequency bands. From laptops to cellular phones to wearables, devices are expected to connect to any cellular, Bluetooth™, GSM, RFID, or other networks. These expectations present challenges when it comes to antenna design, compared to a traditional design. The simplest solution — using discrete antennas for each frequency band required in the application — requires extra physical space. But this ultimately clashes with industry trends that prefer smaller and smaller solutions while still providing more bandwidth.
RF Microwave / Thin Film
EMI Filtering for High-Reliability Applications Amanda Ison AVX Corporation, 11144 Penrose St, Sun Valley, CA 91352www.avx.com Electromagnetic interference (EMI), or electrical noise, is generated by everything from cellphones to solar flares and can make accurate signal transmission as difficult as trying to have a clear conversation in a noisy room. To improve signal clarity in electronic circuits, device designers turn to EMI suppression filters. Effective EMI filtering is necessary for almost every modern electronic device, including devices that generate their own EMI, as well as devices that are sensitive to EMI within their environment, and is especially important in high-reliability applications that utilize lower-power signals and have strict signal fidelity demands. High-reliability EMI filters are designed to consistently meet or
Using High-Directivity Couplers in Isolatorless Cellular Phone PA Control Written By: Avital Yaish Abstract: This article outlines the use of High-Directivity Couplers in Cellular handsets. Benefits can include increased talk-time, minimized insertion loss between the PA and the antenna and can also remove the need for an isolator. A version of this article was previously published in RF Design, April 2006.
Thin-Film Passives in RF/Microwave Circuits Written By: Ron Demcko Abstract: Until recently, most microwave capacitors were based on fired multilayer ceramic technology. In this process, layers of highly conductive electrode metal alloys are interleaved with low-loss ceramic dielectrics in a multilayer fashion until the target capacitance is obtained. The resulting stack is then sintered into a monolithic structure in a high-temperature firing process. This process continues to satisfactorily serve highpower capacitor needs in addition to those in larger value RF capacitors…
The Accu-L Multi-Layer Inductor for High Frequency Applications Written By: Barry N. Breen | Chaim Goldberger | Leonid Talalavsky Abstract: The telecommunications industry today is undergoing changes. The miniaturization of electronic circuits and the use of higher frequencies in radio communication systems such as Cellular Telephones, PCN and GPS places new demands on passive components. High frequency inductors have not kept pace with the demands. AVX has responded to these requirements by putting to market a miniature (0805) high frequency SMD inductor based on thin film technology. This article presents the basic concepts of high frequency inductors and how such low value inductors are measured and characterized. Here, too, there is a lag between the high frequency designer’s need for
Energy and Power Handling Capabilities of Thin Film and Ceramic Capacitors Written By: Ben Smith Abstract: A continual growth of uncertainty and misconception has been prevalent in determining the power and energy capabilities of both ceramic and silicon capacitors. As today’s systems are subjected to increasingly more stringent requirements, designers are faced with numerous situations where the components that are used dictate design configurations. This paper addresses the concepts associated with a capacitor’s ability to withstand power and energy. Both theoretical and empirical models are developed and used to provide design guidelines.
Dielectric Absorption of Multilayer Organic (MLO™) Capacitors Written By: Edgardo Menendez Abstract: Capacitors with Dielectric Absorption (DA) recover some of their charge even after the capacitor has been fully discharged (see Figure 1). (Ref. 2) It is expressed in percentage and it is based on the measured voltage after discharging and charge recovery divided by the maximum voltage that was originally applied (see Equation 1)…
Benefits of Thin-Film Dielectric Chip Capacitors at VHF, UHF, and Higher Frequencies Written By: Barry Breen | Leonid Talalaevsky | Scot Tripp Abstract: Present and future cellular networks and satellite telecommunications systems demand unique performance characteristics from the SMD capacitors incorporated into their designs. To meet these requirements, single layer surface mount capacitors have been developed on the basis of thin film technologies. The capacitor’s single layer thin film construction provides several major performance advantages relative to multilayer chips. These are much improved Q (low ESR), consistent and repeatable Q/ESR/Ceff/SRF parameters, superior power capability, no secondary resonances up to a frequency of 40GHz and very tight tolerance on capacitance value. By virtue of these characteristics and excellent mechanical features, this
Accu-P® Thin-Film Capacitors Act as Band Reject Filters Written By: Avital Yaish Abstract: AVX Accu-P® capacitors exhibit excellent resonance stability which makes them ideal for Band Reject Filters, whereas Ceramic capacitors are unsuitable due to their wide SRF scatter.
A Review of High Frequency Passive Component Technologies (Thin-Film, Thick-Film, Discretes & PMC) for RF Design Applications Written By: Chris Reynolds Abstract: This article traces the evolution of these technologies and discusses the benefits and trade offs for each. The current level of RF component integration available in existing discrete package sizes is discussed, along with trends to tighter tolerance and ultra-stable parametric performance. The article concludes with an update on the emergence of higher levels of integration into passive component networks, and how this is now enabling engineers to optimize their RF designs. A version of this article was published in RF Design, August 2005.