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This paper describes an advanced design systems (ADS) approach of stepped impedance microstrip low pass filter design for maximally flat or Butterworth responses. The cut-off frequency is 4 GHz with source and load impedances of 50 Ω. The insertion loss at passband is 0.5 𝑑𝐵 and stopband is 20 𝑑𝐵. In this filter design, an order 𝑁 = 7 was chosen for maximally flat (Butterworth) filter prototype. Substrate properties such as relative dielectric constant ∈ 𝑟 = 4.2, loss tangent 𝑡𝑎𝑛𝛿 = 0.02, height of dielectric material ℎ = 2.0 𝑚𝑚 and conductor thickness of 0.01 𝑚𝑚 were used in calculation of the length and width of the transmission line. Design of lumped circuit for microwave filter prototype scaled in frequency and impedances is discussed. Equivalent transmission line was obtained by converting lumped circuit into certain lengths and characteristic impedances. ADS simulation software was used to plot maximally flat filter characteristics. The plots show variation of incident wave 𝑆(1,1) and forward gain 𝑆(1,2) with frequency in 𝐺𝐻𝑧.

A STS (System Transfer Specification) energy meter with an embedded solution for two-way communications over Global System for Mobile Communications (GSM), was designed and simulated with Proteus. This meter should be able to report any tampering attempt on the customer’s meter, by sending an SMS (Short Message Service) via Global System for Mobile Communications (GSM) as regards energy theft from the point of theft to an automated meter management station. Every meter is part of an automated metering management network, which is a scaled down version of a conventional Advanced Metering Infrastructure (AMI). This research provides an additional capability to STS energy Meters. The additional two-way communications capability of the Energy Meter is implemented with the addition of a GSM module to a conventional STS meter. The additional functionality to the STS meter real-time reporting was achieved by adding a GSM module to its design.

This paper describes the design of convolutional encoders encoding broadband data with coding rates (r) 3/4 and 5/6 at the transmitter, and the Viterbi decoders for the decoding of the encoded data with same coding rates at the receiver. This design uses BPSK (Binary Phase Shift Keying) modulating scheme in an AWGN (Additive White Gaussian Noise) channel in analysing the BER (Bit-error rate) performance of next generation broadband wireless access systems. The constraint length of the convolutional encoder is K=7, with number of states n=2k-1, and the design was implemented using Matlab Computational Software. The higher coding rates of the convolutional encoders were achieved using puncturing codes and de-puncturing codes for the corresponding Viterbi decoders. In satellite network design, it is vital to compliment the system design with the BER requirement of the network. Plots of BER against SNR ( ) were made for the various coding rates and for data rates of 50000 bits and 12000 bits. The results were analysed based on comparison of coding gain obtained for the different coding rates, theoretical BER and calculated BER. In this paper, Matlab simulation of the convolutional encoder and Viterbi decoder shows improved coding gain for higher data rates and data sequences.