Industry News

A Minimalist Approach to Feedforward Multi-carrier Linear Power Amplifiers

A feedforward multi-carrier linear power amplifier with 60 W maximum average output is featured
Atmospheric propagation attenuation is known to be higher in the 2.1 GHz band than in the cellular band. Thus, to overcome this performance disadvantage and to maximize cell coverage and capacity, Unity Wireless System's first feedforward multi-carrier linear power amplifier (MCLPA) product has been designed with a high 60...
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A Fully-integrated 5 GHz 0.18 µm CMOS VCO for 802.11a WLAN Applications

This article presents a fully-integrated 5 GHz CMOS voltage-controlled oscillator (VCO) for a U-NII band 802.11a WLAN application. The VCO core circuit uses only PMOS fabricated with the 0.18 mm 1P6M standard CMOS process to obtain better phase noise p...
Due to the fast growing demand for broadband wireless communications, the operating frequency is moving toward the 5 GHz U-NII band. With a maximum data rate of 54 Mbps, the IEEE 802.11a wireless LAN (WLAN) standard specifies a 300 MHz allocation of spectrum in the 5 GHz range that...
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Understanding W-CDMA Modulation Quality Measurements

There are many ways of characterizing W-CDMA transmitter performance. However, the Third Generation Partnership Project (3GPP) specifications require two measurements to verify the in-channel modulation quality of W-CDMA transmitters - error vector magnitude (EVM) and peak code domain power (peak CDE). This article explores the purpose behind these key...
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2002 Editorial Index

ANTENNAS Chuang, Huey-Ru, Liang-Chen Kuo, Chi-Chang Lin and Wen-Tzu Chen "A 2.4 GHz Polarization-diversity Planar Printed Dipole Antenna for WLAN and Wireless Communication Applications," No. 6, p. 50. Gunnels, Robert "Axial Ratio Measurements of Single Circularly Polarized Antennas," No. 1, p. 124. Izadian, Jamal S. "QFHA Antennas for Satellite...
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A Measurement-based Behavioral Model for I/Q RF Modulators

This article describes a nonlinear behavioral modeling technique for application to I/Q modulated communication channels. The model data was gathered by independent measurements of an I/Q modulator and amplifier, using vector signal generators and anal...
The W-CDMA standard expresses transmit quality in terms of EVM and ACLR, and receive quality in bit error ratio (BER). These quality measurements are simple scalar numbers representing a very complicated system. Modern communications channels (still) consist of a number of concatenated functions such as baseband (BB) processor, DAC,...
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