The modulation bandwidth and noise limit of a photoconductive sampling gate are studied by reducing the parasitic capacitance and leakage current of the sampling circuit using an integrated junction field-effect transistor (JFET) source follower. The modulation bandwidth of the photoconductive sampling gate is limited by the external parasitic capacitance, and its efficiency is found to saturat...

Feed-forward pre-equalization is investigated to extend the transmission capability of μLEDbased links, providing better receiver sensitivities up to 5dB compared with post-equalization. Errorfree 2Gb/s free-space VLC over 0.6m is demonstrated using a PAM-4 modulated blue μLED and an APD receiver. Introduction Visible light communication (VLC) links for intraroom data communications have been i...

A novel high-order single-loop incremental sigmadelta ADC for multi-channel applications is proposed. Highorder continuous-time architectures are explored using a 3rd order single-bit modulator as a test-case. The performance of the proposed architecture, taking into account critical nonidealities, is analyzed and its advantages and issues are discussed. Behavioral simulations show a key advant...

Wireless communication system, gives good performance only when the selection of modulation process is best. Generally, to chose the particular modulation schemes different parameters are taken into consideration i.e. bandwidth efficiency, bit error rate, signal to noise ratio, cost, effectiveness and easy implementation, but since from very long time bandwidth efficiency is that parameter whic...

Angle modulation, such as phase and frequency modulation (FM/PM), has recently attracted attention for improving the fidelity of analog optical links. This is because angle can enhance signal-to-noise ratio (SNR) original message simply by increasing index or bandwidth. However, direct generation a broadband angle-modulated signal not necessarily easy. On other hand, there an indirect method, w...

The range resolution in conventional continuous time frequency modulation (CTFM) is inversely proportional to the signal bandwidth. The dual-demodulator continuous time frequency modulation (DD-CTFM) processing technique was proposed by Gough et al [1] as a method to increase the range resolution by making the output of DD-CTFM truly continuous. However, it has been found that in practice the r...

In the present time bandwidth efficiency is one of the most important parameter to measure different modulation scheme in digital communication. Due to the separation of waveforms of all the existing modulation schemes in time domain it becomes difficult to improve their bandwidth efficiency. Hence it was become very important for researchers to proposed such a scheme that able to improves the ...