Overcoming the RF challenges of multiband mobile handset design
Jul 1, 2007
By Rodd Novak Demands on components in the RF signal chain of a mobile handset increase
with the number of bandwidths and modes, especially for the antenna and its
switch. The integration capabilities of RF CMOS devices solve many of these
issues while maintaining peak performance....
Alternative to SMT for microwave and millimeter-wave systems
Jul 1, 2007
By Javed Siddiqui, Dan Sundberg and Dominick Suarez Conventional SMT works well for frequencies up to about 6 GHz. However, at higher frequencies SMT is usually not a viable option because in SMT topology the transmission lines are unshielded, and the components do not have adequate grounding. ...
Low additive noise frequency tripler
May 1, 2007
By Bogdan Sadowski Design of a frequency tripler is presented and its noise degradation, due to
the presence of additive noise of the multiplier, is measured and compared to
theoretical limits....
Selecting the right signal combiner
Apr 1, 2007
By Tony Ramsden This article is intended to highlight the benefits of the many options available to today's system engineers. And, thereby, attempts to help the designer in selecting the right signal combiner for the desired application....
ESD-protected RF filter with on-chip passive and active elements
Nov 1, 2006
By H. Böhm, H. Kebinger, R. Losehand, and H. Heiss A monolithic integrated multiband PCN/PCS RF-bandpass filter manufactured
on highly resistive silicon substrate with mode conversion and ESD protection is
described. In order to analyze the ESD behavior of the filter, an ESD simulation
model is presented and compared with measurement results....
Design and performance of precision miniature TCXOs
Sep 1, 2006
By Steve Fry This article will describe the current state-of-the-art in TCXO temperature-compensation
technology and the associated crystal resonators....
Reducing the design complexity of next-generation handsets
Sep 1, 2006
By Jennifer Chou This article will discuss the many available modulation technology options that are used for various EDGE systems, including direct-launch conversion transmitter (DCT),
small-signal polar modulation (sometimes called “polar lite”), and large-signal open polar modulation, and compare them to the more effective, large-signal closed polar loop solution that delivers the best overall system performance and ease of
manufacturing....
Using high-directivity couplers in cell phone PA control
Apr 1, 2006
By Leonid Talalaevsky This article presents a wideband high directivity coupler that replaces isolators and provides better control of PA output at lower cost and smaller size....
Next-generation wireless propels GaN power transistors, CMOS RFICs and passives
Jan 1, 2006
By Ashok Bindra, editorial director; Mark Valentine, technical editor; and Keith Vick, technical contributor This special report focuses on the latest advances in gallium nitride (GaN) power
transistors for microwave and millimeter-wave applications, CMOS RFICs and
passive components....
All Terminators Are Not Created Equal
Nov 1, 2005
By Jerry Seams Variations in physical construction can cause resistors that are dc-equivalent to have drastically different electrical characteristics at radio and microwave
frequencies....
Designing Filters Efficiently Using Simulation Tools
Sep 1, 2005
By Anurag Bhargava Filters are an integral part of any RF/microwave system. Designing one efficiently
and accurately can be a challenge, even when sophisticated simulation tools are
available. Electromagnetic simulation, which is more or less an integral part of
any commercial RF/microwave simulation software, can help designers meet this
challenge. As an example, this article gives two bandpass filter (BPF) examples
that were simulated using circuit and electromagnetic (EM) simulators and
compares the simulated and measured results....
Passives for RF design
Aug 1, 2005
By Chris Reynolds Designers can choose from fully integrated systems or fully discrete solutions with their associated pros and cons. Both thin film and PMC are rapidly developing technologies, and a number of new devices will soon be emerging. The PMC process is ideal for integration of the passive content of the RF circuit to optimize PA or LNA performance for a given application....
