This paper describes the design of a programmable FSK-modulator based on VCO and its implementation in 0.35m CMOS process. The circuit is used to transmit digital data at 100Kbps rate in the frequency range of 400-600MHz. The design and operation of the modulator is discussed briefly. Further the characteristics of PLL, frequency synthesizer, VCO and the whole design are elaborated. The variati...

This paper describes the architecture of a new pure digital frequency synthesizer based on pulse generators, counters and a register. The technique described here is much simpler than other methods. The synthesizer presented is suitable for the design of VLSI architectures or for programmable large-scale integration circuits.

We have used the frequency comb generated by a femtosecond mode-locked laser and broadened to more than an optical octave in a photonic crystal fiber to realize a frequency chain that links a 10 MHz radio frequency reference phase-coherently in one step to the optical region. By comparison with a similar frequency chain we set an upper limit for the uncertainty of this new approach to 5. 1x10(-...

Frequency synthesizers are an essential part of any modern transceiver system. They generate clock and oscillator signals needed for up and down conversion. Today’s communication standards demand both high frequency accuracy and fast frequency settling. The fine frequency resolution, low spurious signals, accuracy and stability are most important for these devices. In this paper, the new freque...

This paper first presents the architecture of a frequency synthesizer which can support multistandard wireless systems of GPS, Galileo, and WCDMA standards. Then, a programmable integer/fractional combined frequency divider (CFD), which is the key building block of the proposed frequency synthesizer, is designed and implemented by using 0.18μm RF CMOS process. The CFD mainly consists of an inte...

A 4 GHz PLL (phase-locked loop)-type frequency synthesizer has been implemented in the standard 0.18μm mixed-signal and RF 1P6M CMOS technology. It integrates a VCO, a dual-modulus prescaler, PFD, a charge pump, a control logic, various digital counters and digital registers onto a single chip. With the help of the linear model of the loop, the design and optimization of the loop parameters are...

In this seminar, a ultra-low-power (ULP) frequency synthesizer design for a battery-less IoT transceiver is explained. Firstly, a theoretical basics of LC VCO (Voltage-Controlled Oscillator) is discussed especially about the trade-off between phase noise and power consumption, which can be indicated by FoM. The limit of FoM is determined by VCO topology and LC-tank quality factor. Variants of V...

Direct Digital Frequency Synthesizer Pentomics’ first DDS patent concerns a method and apparatus for DDS which, unlike the traditional table-lookup methods, uses a simplified “angle-rotation” algorithm implemented as a multiplierless feedforward datapath, allowing easy pipelining and limiting the accumulation of roundoff errors. Our DDS’s modular architecture permits outputs of arbitrary precis...

This report considers two well-known methods of frequency synthesis, the VCO approach and the modular or iterative mix-filter-divide approach from the point of view of use in the Lincoln Experimental Satellite (LES) series. System parameters are chosen and a specific implementation is described. Accepted for the Air Force Franklin C. Hudson Chief, Lincoln Laboratory Office

This thesis studies the level of performance achievable using today's standard IC processes in the integrated RF subcircuits of the modern GSM base station. The thesis concentrates on those circuit functions, i.e. I/Q modulators, variable gain amplifiers and frequency synthesizers, most relevant for integration in the base station environment as pinpointed by studying the receiver/transmitter a...