Christopher S

In this paper, a 2 inverted U-slot integrated rectangular patch antenna array is proposed that can be used for S band applications i.e., radar applications, communication and wireless networks. In the proposed antenna design 2 inverted U slots are introduced in the patch to improve bandwidth providing a bandwidth of 150 MHz and gain of 4.08 dBi resonating at 3.3 GHz. Furthermore, 4 X 4 antenna array is fabricated on 1.6 mm thick FR4 substrate with dielectric constant 4.4 providing a gain of 14.2 dBi. Ansys HFSS is used for antenna simulation and a prototype is fabricated and tested.

A CMOS down-converter with the combination of Gilbert Cell mixer and modified low voltage design technique using LC-balun is demonstrated in this paper. This forms a down-converter duo of mixer and balun. The RF, LO, and IF port frequencies are 3 GHz, 2.4GHz, and 600MHz, respectively. The measurement results of the proposed mixer-balun duo exhibit 13dB of conversion gain, -7.9 dBm of Input 1-dB compression point (P1dB), 2.51 dBm of Input 3rd order intercept point (IIP3), 3.8 dBm of Output 3rd order intercept point (OIP3) -43dB RF-IF, -42dB LO_IF Isolation and 1.2V supply voltage. This mixer-balun duo was fabricated at 65nm. CMOS technology. It can provide a 4 dB conversion gain even without connecting the LC-balun and 1.2V supply voltage is utilized.

The design details of K band 6 bit digital phase shifter circuit in 65nm CMOS technology (MMIC) for phased array antennae in general and active phased array antennae in particular, are presented in this paper. The circuit is composed of Si CMOS switches and filter based phase shifting network. The 6 bits are designed individually using the lumped equivalents and then connected together. The switches form an integral part of the design. The parasitic impedances associated with the switches are compensated in the design. With 6 bits, a total of 64 states are derived with different switching combination, and coverage of 360 is achieved. The insertion loss is observed to be -13± 6.5 dB and the input and output matching was greater than 5 dB over the band of 19-20 GHz. The RMS phase error achieved is 3° at the centre frequency of 20 GHz. The area of the design is 1.255 mm × 0.424 mm, the circuit operates at 1.2V and the power consumed is almost low.

In this paper, a miniaturised wide-band circular slot cut patch antenna with broad beam width is proposed that can be used for X band applications i.e., radar, satellite and wireless computer networks. In this proposed antenna design, initially a circular patch is taken and then 2 circular slots are removed from the patch to get wide band and broad beam-width providing 1.67 GHz (17%) of bandwidth, beam-width (HPBW) 100° in E-plane (i.e., φ=0o) and 96° in H-plane (i.e., φ=90o) and more than 100° beam-width for higher frequency within the operating bandwidth. The proposed design provides 5.5 dBi-4.43 dBi of gain over the band. For miniaturising and furthermore improvement of bandwidth and beam-width capacitive via fence is introduced around the patch antenna providing 2.03 GHz (22%) of bandwidth and more than 125° of beam-width. Ansys HFSS is used for antenna simulation and a prototype has been fabricated.

A novel photonic sub-Nyquist based wideband frequency measurement system based on a pulsed laser, a set of interleavers and a binary deduction algorithm is proposed and verified with simulations.

In general, bearing measurements combined with the derived heading increases the accuracy of target state estimate in bearing only tracking (BOT). Here, Lagrange five point difference (LFPD) method is proposed for deriving the heading measurements. This method is compared with Lagrange three point difference (LTPD) and centered difference (CD) method by considering the scenario of two sensors tracking a single target. The bearing and derived heading measurements from two sensors are fused using measurement fusion (MF) technique. The nonlinear Extended Kalman filter (EKF) is implemented using fused measurement to obtain the optimized target state estimate. Performance analyses are made between LFPD compared with LTPD and CD by considering without and with fusion technique. Simulation results indicate MF-LFPD performs comparatively better.