Design of cascaded all pass network with monotonous group delay response for broadband radio frequency applications

In this study, an iterative procedure is developed for designing radio frequency circuits with a specified group delay dispersion (GDD) characteristics over a broad bandwidth. Second order all pass networks (APNs) are cascaded systematically over multiple stages to achieve the same. The approach is flexible enough to design circuits for various group delay responses. This is demonstrated using two-stage APN with both positive and negative slopes of linear and non-linear group delay responses for a frequency band of 500 MHz-1 GHz. The proposed multi-stage design procedure is shown to help extend the bandwidth over which a uniform resolution of frequency discrimination is possible. Practical limitations in implementing this circuit are addressed while developing the prototype. The circuit is realised as a surface mount device-based implementation of modified two-stage APN. The realised circuit has a GDD of -6 ns/GHz and an insertion loss of 1.2 dB for 500 MHz-1 GHz band. The performance parameters such as GDD, insertion loss and device footprint of the proposed approach are significantly better than previously reported.

[1]  Ming Li,et al.  An Unbalanced Temporal Pulse-Shaping System for Chirped Microwave Waveform Generation , 2010, IEEE Transactions on Microwave Theory and Techniques.

[2]  S. Hellerstein,et al.  Synthesis of All-Pass Delay Equalizers , 1961 .

[3]  E. G. Cristal.  Analysis and Exact Synthesis of Cascaded Commensurate Transmission-Line C-Section All-Pass Networks , 1966 .

[4]  José Azaña,et al.  Ultrahigh dispersion of broadband microwave signals by incoherent photonic processing. , 2010, Optics express.

[5]  D.V. Plant,et al.  A Fully Electronic System for the Time Magnification of Ultra-Wideband Signals , 2007, IEEE Transactions on Microwave Theory and Techniques.

[6]  S. Gupta,et al.  Multilayer Broadside-Coupled Dispersive Delay Structures for Analog Signal Processing , 2012, IEEE Microwave and Wireless Components Letters.

[7]  M. J. Garde,et al.  Real-Time Spectrum Analysis in Microstrip Technology , 2001, 2001 31st European Microwave Conference.

[8]  José Azaña,et al.  Optical frequency domain reflectometry based on real-time Fourier transformation. , 2007, Optics express.

[9]  D.V. Plant,et al.  An electronic temporal imaging system for compression and reversal of arbitrary UWB waveforms , 2008, 2008 IEEE Radio and Wireless Symposium.

[10]  Qingfeng Zhang,et al.  Analog Signal Processing: A Possible Alternative or Complement to Dominantly Digital Radio Schemes , 2013, IEEE Microwave Magazine.

[11]  K. J. Vinoy,et al.  Real-time frequency discriminator using two stage all-pass network , 2014, 2014 IEEE International Microwave and RF Conference (IMaRC).

[12]  A. S. Bhushan,et al.  Photonic time stretch and its application to analog-to-digital conversion , 1999 .

[13]  Alyssa B. Apsel,et al.  A distributed amplifier based dispersive delay line , 2011, 2011 IEEE International Symposium of Circuits and Systems (ISCAS).

[14]  Qingfeng Zhang,et al.  All-pass dispersion synthesis using microwave C-sections , 2014, Int. J. Circuit Theory Appl..

[15]  B Nikfal,et al.  Increased Group-Delay Slope Loop System for Enhanced-Resolution Analog Signal Processing , 2011, IEEE Transactions on Microwave Theory and Techniques.

[16]  Blaise Ravelo,et al.  Similitude between the NGD function and filter gain behaviours , 2014, Int. J. Circuit Theory Appl..

[17]  Etienne Perret,et al.  Chipless RFID based on group delay encoding , 2011, 2011 IEEE International Conference on RFID-Technologies and Applications.

[18]  Etienne Perret,et al.  Group-Delay Engineered Noncommensurate Transmission Line All-Pass Network for Analog Signal Processing , 2010, IEEE Transactions on Microwave Theory and Techniques.

[19]  Zhongtao Fu,et al.  Theoretical Analysis and Practical Considerations for the Integrated Time-Stretching System Using Dispersive Delay Line (DDL) , 2012, IEEE Transactions on Microwave Theory and Techniques.

[20]  R. Levy.  Realization of Practical Lumped Element All-Pass Networks for Delay Equalization of RF and Microwave Filters , 2011, IEEE Transactions on Microwave Theory and Techniques.

[21]  K. J. Vinoy,et al.  Group delay engineering using cascaded all pass filters for wideband chirp waveform generation , 2013, 2013 IEEE International Conference on Electronics, Computing and Communication Technologies.

[22]  Qingfeng Zhang,et al.  High-resolution real-time spectrum sniffer for wireless communication , 2013, 2013 International Symposium on Electromagnetic Theory.

[23]  G. Wilson.  RC active variable group-delay equalizers with independent Q and ω controls , 1977 .

[24]  J. Rhodes.  Filters approximating ideal amplitude and arbitrary phase characteristics , 1973 .

[25]  S. Gupta,et al.  Compressive Receiver Using a CRLH-Based Dispersive Delay Line for Analog Signal Processing , 2009, IEEE Transactions on Microwave Theory and Techniques.

[26]  Su Yu,et al.  Group Delay Variations in Microwave Filters and Equalization Methodologies , 2013 .

[27]  Blaise Ravelo,et al.  Methodology of elementary negative group delay active topologies identification , 2013, IET Circuits Devices Syst..

[28]  R. Crane,et al.  All-Pass Network Synthesis , 1968 .