Over-the-air performance testing of wireless devices with multiple antennas
Feb 1, 2006
By Michael D. Foegelle The proliferation of wireless devices has led to the development of new
technologies that combine the use of multiple antennas with special algorithms
that can dynamically change the RF performance of the device. Measuring the
performance of these new technologies poses signifcant challenges to current
test methodologies....
High-performance active mixer overcomes RF transmitter design challenges
Jan 1, 2006
By James Wong A new generation of high-performance active mixers like LT5521 offers a combination of high linearity, low noise, easy LO drive, and with little or no conversion loss, resulting in a cost-effective, high-performance solution....
A direct-conversion transmitter for WiMAX and WiBro applications
Jan 1, 2006
By Cecile Masse The use of high data rate OFDM modulation translates into challenging requirements for the transmitter in terms of spectral quality and EVM. This calls for low distortion, good signal balance and low phase error. This article will
focus on the challenges and advantages associated with implementing a direct
conversion transmitter....
Silicon TV tuners poised to replace cans
Oct 1, 2005
By Alvin Wong and Jordan Du Val While the evolution of TV receivers has accelerated on many fronts in the last
decade, fully integrated silicon tuner design has lagged behind this evolutionary
wave. The silicon TV tuner is now perfected and will rapidly replace traditional
can tuners, just as transistors replaced vacuum tubes during the mid-1960s....
RF MEMS in mobile phones
Sep 1, 2005
By Refugio Jones and Mark Chapman The need for multiband, multimode band switching at low insertion loss
while maintaining excellent linearity in mobile phones is driving the need for
RF MEMS-based switches. Since this switching problem gets even more acute
as new complex waveforms, such as WiMAX are added to this mix, this article
looks at the current state of development in RF MEMS switches and discusses
its impact on 3G cellular phones....
Digital step attenuators offer precision and linearity
Aug 1, 2005
By Radha Krishna Setty Super RF CMOS process technology has been used to develop digital step attenuators that offer an unprecedented combination of accuracy, linearity, programmability, ESD tolerance and wide bandwidth in a miniature surface-mount package....
Advances in handset antenna design
May 1, 2005
By Simon Kingsley This article shows how dielectrics can be used to improve the performance of electrically small antennas, as well as describes techniques to integrate the antenna, also known as an aerial, with the radio to create an antenna module....
Active downconverting RF mixer offers high linearity
Apr 1, 2005
Optimized to offer high linearity and wide dynamic range, Linear Technology's active downconverting RF mixer LT5527 brings a high level of integration...
Antennas are getting the needed attention
Apr 1, 2005
Ashok Bindra, Editorial Director While antennas, also known as aerials, have been around since the birth of radio, it was always looked upon as a mundane passive component that must be...
Frequency divider design strategies
Mar 1, 2005
By Louis Fan Fei Typically, in frequency divider design, the trade offs are around the maximum
operating frequency, power consumption, number of transistors needed and
flexibility. Depending on the specific application the frequency divider is used,
analog or digital approaches may be adopted. This paper will cover the
fundamentals of both approaches....
Wafer-scale integration brings low cost and a small footprint to active antenna arrays
Feb 1, 2005
By Fred Mohamadi Fabricating a 256-element steerable antenna array on an eight-inch wafer is
quite a feat, given the multitude of issues—steering the antenna, optimizing the
RF paths and the like. By addressing these and other matters, one at a time, it
becomes clear that realization is well within reach....
