The applications for the LMX2240 IF Receiver are discussed. Practical limitations of high frequency IF demodulators are examined, and methods to cope with these limitations are introduced. Specifically, methods to reduce the susceptibility to oscillation are given, and include layout considerations as well as circuit implementations. In addition, the demodulator tank circuit is examined in deta...

An efficient mixed-mode Gaussian frequency-shift keying (GFSK) demodulator with a frequency offset cancellation circuit is presented. The structure is suitable for a low-IF Bluetooth receiver and can also be applied to other receivers involving continuous phase shift keying (CPSK) signals. The demodulator implementation is robust to tolerate process variations without requiring calibration. It ...

Despite the advantages that quadrature mixing offers to radio front-ends, its practical use has been limited due to its sensitivity towards gain and phase mismatches between its in-phase and quadrature channels. DC offsets are also a problem when a zero-IF transceiver topology is used. In this paper, novel digital compensation techniques are introduced to extract and correct the quadrature imba...

In this paper a robust, single carrier, multi-user, DSP-based implementation of an OFDM, differential phase shift keying (DPSK) block demodulator is suggested. It is shown that a direct, DSP-based implementation of the above system using a single FFT symbol is highly susceptible to artifacts induced by symbol timing errors (symbol synchronization jitter, SSJ). A dual symbol, FFT-based implement...

Abstra t: A robust soft-de ision hannel optimized ve tor quantization (COVQ) s heme for Turbooded AWGN hannels is proposed. The log-likelihood ratio (LLR) generated by the Turbo de oder is exploited in the COVQ design via the use of a q-bit s alar soft-de ision demodulator. The on atenation of the Turbo en oder, modulator, AWGN hannel, Turbo de oder, and q-bit soft-de ision demodulator is model...

Why DSP? You may wonder “What’s the big deal?” Why are so many of the new radios supplied with DSP demodulators and filters? It’s because digital techniques have several advantages over their analog counterparts. Probably the most exciting aspect of this is that everything is done in software. This means that when I design a new demodulator, you can download it to your radio and you then have m...

A comparison of various low-pass filter architectures that are commonly used in Sigma-Delta ( C A ) demodulators is presented in the paper. In this comparison the conventional demodulator filter architectures such as the optimal FIR filter, Sinck filter and non-linear Zoomer filter are considered. It is shown that the optimum FIR filter provides the most attractive properties among the conventi...

A direct conversion modulator-demodulator with even harmonic mixers with emphasis on noise analysis is presented. The circuits consist of even harmonic mixers (EHMs) realized with antiparallel diode pairs (APDPs). We evaluate the different levels of I/Q imbalances and DC offsets and use signal space concepts to analyze the bit error rate (BER) of the proposed transceiver using M-ary QAM schemes...

In the last few years, works have been published about demodulating Single Fringe Pattern Images (SFPI) with closed fringes. The two best known methods are the regularized phase tracker (RPT), and the two-dimensional Hilbert Transform method (2D-HT). In both cases, the demodulation success depends strongly on the path followed to obtain the expected estimation. Therefore, both RPT and 2D-HT are...

This work deals with the design of a simple double output voltage phase detector, using specific type analog multiplier, and its application in frequency demodulator. The active parts was performed Taiwan Semiconductor Manufacturing Company (TSMC) $0.18~\mu \text...