Recent work on speech synthesis by rule has led to the design and evaluation f a new digital formant synthesizer. The synthesizer was simulated ona digital computer at a 20-kHz sampling frequency. The improvements over previous synthesizers include: an excitation sonrce for the unvoiced compm•eut of voiced fricatives; a method for producing a voice bar for the closure p riod ofvoiced stops; and...

Frequency synthesizers are used in a large number of time division multiplexed (TDMA) and frequency hopping wireless applications where quickly attaining frequency lock is critical. A new frequency synthesizer is described which employs a scheme for reducing lock time by a factor of two using a conventional phase locked loop architecture. Faster lock is attained by shifting the loop filter’s ze...

Frequency synthesizers are used in a large number of time division multiplexed (TDMA) and frequency hopping wireless applications where quickly attaining frequency lock is critical. A new frequency synthesizer is described which employs a scheme for reducing lock time by a factor of two using a conventional phase locked loop architecture. Faster lock is attained by shifting the loop filter’s ze...

Frequency synthesizers come in a variety of forms ranging from tiny PLL chips and moderate-size modules to bench-top signal generators [1-5]. Single-chip synthesizers are available in a die form or as surface-mount integrated circuits. They include key elements (such as RF and reference dividers, phase detector, lock indicator, etc.) required to build a simple single-loop PLL synthesizer. More ...

With the advances in wireless communication technology over last two decades, the use of fractional-N frequency synthesizers has increased widely in modern wireless communication applications due to their high frequency resolution and fast settling time. The performance of a fractional-N frequency synthesizer is degraded due to the presence of unwanted spurious tones (spurs) in the output spect...

A quantization noise reduction technique is proposed that allows fractional-N frequency synthesizers to achieve high closed loop bandwidth and low output phase noise simultaneously. Quantization induced phase noise is the bottleneck in state-ofthe-art synthesizer design, and results in a noise-bandwidth tradeoff that typically limits closed loop synthesizer bandwidths to be <100kHz for adequate...

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...