Products
Oct 1, 2006
AFIXM daughter card Radstone Embedded Computing has announced an addition to the AFIX (additional flexible interface Xtension) family of plug-on daughter...
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....
High-power gallium nitride transistors inch forward
Jun 1, 2006
Ashok Bindra, Editorial Director Slowly, but steadily, gallium nitride (GaN) power transistors are moving forward. Every year the progress report looks better and commercial viability...
RF PA linearity in GSM transmitters
May 1, 2006
By Oleksandr Gorbachov Nonlinearity in GSM PAs for digitally modulated signals is acceptable within certain limits, beyond which phase error becomes a problem. Although IMD has only negligible effects on phase error, higher-order IMD products have a more severe effect on spectral re-growth....
Dual, quad op amps operate from 1.8 V
Mar 2, 2006
Linear Technology has introduced the LT6001 and LT6002, 1.8 V dual and quad operational amplifiers available in a tiny DFN package....
Artificial Neural Networking Improves PA Design
Mar 1, 2006
By Jarno Kyhälä Artificial neural networking can be used to aid the design work of the device such as a power amplifier. This paper will discuss the ANN model generator implemented in the APLAC simulator, and show how ANN can be more efficient than conventional interpolation. It will also demonstrate the usefulness of ANN in electronics design using an example of optimizing a matching network for a power amplifier....
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....
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....
Push-pull amplifiers improve second-order intercept point
Nov 1, 2005
By Radhakrishna Setty Wideband communications systems have signals occupying multi-octave frequency ranges. Such signals, when amplified in conventional amplifiers, can be distorted due to the second-order products generated inside the amplifier. An ideal push-pull amplifier can cancel the internally generated products and preserve the signal quality. ...
Increasing the speed of testing GSM/EDGE mobile phone power amplifiers
May 1, 2005
By Roland Minihold, Rohde & Schwarz Munich, Germany Testing is one of the critical operations necessary to ensure that GSM/EDGE mobile phones meet their required specifications. Consequently, reducing this...
Tightening the screws in RF power measurement
Apr 1, 2005
By Carlos Calvo and Anthony Mazzei Using a combination of a logarithmic amplifier and a temperature sensor it is possible to design a temperature compensation scheme to significantly reduce the contributions of the two major error factors in RF power management, temperature and process variations. In some cases, the temperature compensation hardware is integrated onto the power detector chip....
GSM/GPRS quad band power amp includes antenna switch
Nov 1, 2004
Combining gallium arsenide (GaAs) power amplifier circuit with integrated passive devices (IPDs) and microvia high-density interconnect (HDI) technology,...
