Opt Quant Electron (2012) 44:403–414 DOI 10.1007/s11082-012-9555-2 Two building blocks of microwave photonics filters in the presence of group delay ripple: a comparative survey Arash Mokhtari · Mahmood Akbari Received: 24 January 2011 / Accepted: 23 January 2012 / Published online: 5 February 2012 © Springer Science+Business Media, LLC. 2012 Abstract We have developed an analytic approach to investigate the effect of group delay ripple of the dispersive devices on the performance of two major building blocks of micro- wave-photonic filters. Firstly, performance of PM-based block in the presence of an arbitrary group delay ripple (GDR) is analyzed and compared with the ripple-free case to reveal the destructive effects of added group delay ripple. In the next step, we repeat the proposed approach for the AM-based one; again, the performance is compared with the ripple-free case. Two distortion metrics are also introduced to quantify this distortion. Comparison of the performance of two building blocks in the presence of group delay ripple unveils some interesting characteristics of microwave-photonic filters which have not been mentioned so far. We also add a general survey of two analyzed building blocks to present their respective most significant advantages and shortcomings. The simulated Optisystem results conform to our proposed analytical approach and verify the theoretical model. Keywords Discrete optical signal processing · Electro-optical devices · Fiber Bragg grating · Phase modulation · Microwave 1 Introduction High speed microwave signals processing is always a challenge. An interesting solution to overcome the common problem of low bandwidth of microwave circuits (referred as “electronic bottleneck”) comprises the employment of photonics technology to perform the required signal processing functionalities of RF signals directly in the optical domain. Imple- mentation of unique properties of photonic devices such as high time-bandwidth product, low loss, electromagnetic interference immunity and light weight leads to a novel research direction called “Microwave-Photonics”(Capmany and Novak 2007). A. Mokhtari (B ) · M. Akbari Department of Electrical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11155-9363, Tehran, Iran e-mail: amokhtari@ee.sharif.edu 123