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A 12-bit partial segmented current steering digital to analog converter (DAC) with low glitch area, power consumption, and integral nonlinearity (INL) error is proposed in this work. The cause of the glitch area and its possible solutions are explored. A current-mode logic (CML) latch with reduced output swing (Vdd to slightly below threshold voltage) is used at the input to the differential switch which reduces the glitch area (also known as glitch energy) significantly to 0.25 pVs. Further, this latch is used in the digital block of the proposed DAC to reduce the area and power requirement of the overall design. A dummy switch is used at the output of the differential switch to diminish effect of charge feedthrough at the output node of a current steering DAC. It also helps in the reduction of minimum allowable voltage headroom as compared to conventional double cascode structure and reduction of total power consumption to 9.1 mW operating at 200 MHz. The design and simulation of current steering DAC are performed in a 0.18 μm standard CMOS technology library using Cadence Virtuoso tool with a supply voltage of 1.8 V.

A 105 dB.Hz2/3 spur free dynamic range (SFDR) is achieved from a semiconductor-based intensity modulator. This has been realized by introducing an injection-locked passively mode-locked laser into one of the arms of a Mach-Zehnder interferometer.

A simple-but-efficient calibration-spur reduction technique is introduced that utilises the digital-and-analogue hybrid return-to-zero (HRZ) method in a current-steering DAC employing a round-robin-fashioned background current-source calibration scheme. A simulation with a 12 b 500 MS/s current-steering DAC showed 9.9 and 7.8 dB improvements in the spur-free dynamic range and signal-to-noise + distortion ratio, respectively, owing to the reduced calibration spur by the proposed HRZ technique.

Cancellation of common-mode intensity noise in microwave-photonic links is found to be limited by the applied intensity modulation. A model is developed and verified experimentally for the dependence of the maximum noise suppression on modulation index, for two-tone and multichannel modulation. For example, for a root-mean-square modulation index of 0.3, suppression is limited to 5 dB.

In this paper we analyze the linearity of a PNP structure based silicon electro-optic modulator. This modulator has shown a high spur free dynamic range (SFDR) of 99.8dB and a relatively low optical loss of 4dB.

A 120 dB. Hz 2/3 spur free dynamic range (SFDR) is achieved directly from a resonant cavity interferometric linear intensity modulator. Also, the dependence of the SFDR of this modulator on the bias point is studied.

We report the performance of a wideband image rejection microwave downconverter which maps 0.8-8.8 GHz signals into intermediate frequencies between 1-2 GHz. Measurements performed on the system reveal an image rejection of greater than 150 dB and a spur free dynamic range of 106 dB/Hz/sup 2/3/. In addition, spurious signals present in the original system have been removed.

Microwave links have become key components in many communications, defense, and scientific optical system applications. Therefore work continues to devise new link technologies and system concepts that maximize link performance. In this paper we review recent progress towards high spur-free dynamic range links, comparing the most attractive new approaches, those using optical phase modulation (PM), with the well-established reference standard - the Mach-Zehnder-modulator based link. It becomes evident that links using differential PM offer some practical advantages, but with only modest performance improvements. In contrast, PM using coherent detection can offer very high performance, but large technical barriers remain.

We describe the advantages of adopting coherent technololgies for the high fidelity transmission of microwave signals via photonic links. The resulting enhancement of the link’s figures-of-merit such as its spur free dynamic range will be presented.

It is reported that the spur-free dynamic range (SFDR) of an optically homodyned serrodyne signal depends on the relative phase difference between the beating optical waves. By optimising this parameter, a 1 MHz tone with 63 dB SFDR has been synthesised, which is the highest serrodyne SFDR ever reported

A modified dynamic element matching algorithm, based on splitting the unit element set into subsets, is proposed. Simulations show that it can improve the spur-free dynamic range of data-weighted averaging significantly, without degrading its signal-to-noise ratio.

Injection locking is demonstrated to improve the analogue performance of long wavelength VCSELs. The third-harmonic spur-free dynamic range was improved by 9 dB/Hz/sup 2/3/ to be 93 dB/Hz/sup 2/3/, and the modulation bandwidth was increased twofold.

Methods to simplify digital frequency synthesizers based on the co-ordinate rotation digital computer (CORDIC) algorithm are presented. Application of these methods leads to performance enhancement, compared with the topologies previously proposed in the literature. For a given output precision, hardware resources are reduced and spur-free dynamic range is increased.