RF & Microwave Industry News

RSS

With the emphasis today on smaller and lighter cellular phones, battery size and weight is of paramount importance. Talk time, however, must not suffer. Therefore, low DC current consumption is a must. This relates specifically to the power amplifier since it is the main current drain in the handset....

Mobility is an undeniable and unstoppable trend. It is the driving force behind wireless connectivity, allowing people to be connected to information and entertainment whenever they want, wherever they go. The applications for wireless connectivity are virtually limitless — from cell phones, laptop computers and personal digital assistants (PDA)...

Due to the fast development of wireless communications, a low cost, high performance, high integration technology is needed for system-on-a-chip (SoC) implementation. CMOS technology provides a good solution for SOC integration. 1 Recent improvements of the standard CMOS process make it possible to implement RF blocks, such as low...

Monolithic logarithmic amplifiers (log amps) can handle signals with dynamic ranges up to 100 dB. They are capable of responding to RF bursts that are as short in duration as a few tens of nanoseconds. However, when demodulating logarithmic amplifiers are used to detect fast RF bursts, strange tails...

Multifunction modules are built from many simpler building blocks. Each block can be in the form of an MMIC device, a discrete component or a hybrid device. These blocks are assembled next to each other and connected by transition lines. There are several disciplines for the assembly process. The...

In the past, voice transmission was the main issue in communications. However, new requirements have evolved from voice to data and mobile communications, which demand a larger amount of information and better quality. Because of these requirements, more complex modulation and demodulation schemes and broadband channel bandwidths are necessary...

A phase-locked loop (PLL) is a popular method used in frequency synthesizers for most communication systems. 10 The block diagram of a common PLL synthesizer is shown in Figure 1 and includes a charge pump phase detector (PD), a temperature-compensated crystal oscillator (TCXO), a voltage-controlled oscillator (VCO), an R...

In this article a temperature dependent equivalent circuit of a forward-biased PIN diode is discussed. Using this equivalent circuit, the temperature behavior of a PIN diode attenuator circuit is analyzed and test results are presented. A novel control circuit is also offered for temperature invariant variable attenuation over a...

Highly accurate microwave systems derive their frequency stability from lower frequency reference oscillators, crystals or atomic standards. The resulting phase noise is, ideally, the lower frequency reference oscillator noise multiplied by 20 log N, where N is the frequency multiplication factor. In microwave systems, this factor can be very...

Power Amplifier for CDMA Handsets This RF power amplifier (RMPA0965) is optimized for CDMA2000-1X applications in the 824 to 849 frequency band. It has single positive-supply operation, low power and shutdown modes, and provides 40% CDMA mode efficiency at 28 dBm average power output. Its high/low power modes optimize...