Design of low loss tem coaxial cavity bandpass filter

This paper presents a design of coaxial cavity bandpass filter that utilizing the method of tapped-input coupling. The design procedures have assumed lossless lowpass prototypes, thus yielding lossless bandpass filters. A systematic filter development using lowpass prototype as a starting point to produce four-pole Chebyshev bandpass response is demonstrated. The coaxial cavity filter has the center frequency of 2.5 GHz and bandwidth of 160 MHz. The insertion loss of 0.1 dB insertion loss and return loss better than 20 dB is achieved especially in the passband. This class of filter would be useful in microwave systems where the low insertion loss and high selectivity are crucial, such as in a base station, radar and satellite transceivers

Substrate Integrated Waveguide Filters Based on Even- And Odd-Mode Predistortion Technique

Novel techniques for the design of predistorted Substrate Integrated Waveguide (SIW) bandpass and bandstop filter are presented. The techniques allow for the realization of lossy filters with ideal lossless transmission and reflection response, offset by a constant amount. Two prototype third-degree Chebyshev bandpass and Inverse Chebyshev bandstop filters are proposed and designed. The two SIW filters having the same center frequency of 6.5 GHz and bandwidth of 125 MHz are implemented on RT/Duroid 4350 substrate with thickness of 0.508 mm. Experimental results show excellent agreement with simulated performance. These new class of filters would be useful in microwave systems where the increased insertion loss can be tolerated, such as in a satellite IMUX

Design of Wide-band Power Amplifier based on Power Combiner Technique with Low Intermodulation Distortion

RF power amplifiers are one of challenging blocks in designing radio frequency transceivers, this is due to non-linearity behavior of power amplifiers that leads to inter-modulation distortion. This paper presents the design of wide-band power amplifier which combined with parallel coupled line band pass filter at the input and output of power amplifier to allow the only required frequency band to pass through the power amplifier. Class-A topology and ATF-511P8 transistor are used in this design. Advanced Design System software used as a simulation tool to simulate the designed wide-band power amplifier. The simulation results showed an input return loss (S11) which less than -10dB, and gain (S21) is higher than 10 dB over the entire frequency band and considers as flat as well. The designed amplifier is stable over the bandwidth (K>1). Inter-modulation distortion is -56.919dBc which is less than -50dBc with 10dBm input power. The designed amplifier can be used for the microwave applications which include weather radar, satellite communication, wireless networking, mobile, and TV

A new energy consumption technique for mobile ad hoc networks

A dynamic temporary network is created through wireless mobile nodes without the need for considerable infrastructure as well as a central manager. In a mobile ad hoc network, routing protocols allow a mobile for transmission and receiving packets. In the last decade, many variants have come up for the AODV. A minimum number of hop counts are chosen for enhancing routing protocols to include additional factors that can have an impact on path selections. As the distance between each node grows, the transmission power also rises accordingly. Hence, this impacts the network’s entire performance and the most important feature is the quality of service. Most of the traditional routing protocols include energy consumption levels of the nodes and various parameters, like residual battery power, consumption of energy per packet and energy needed per transmission. A new technique is proposed in this paper to enhance the routing efficiency by making use of lion optimization algorithm after identifying all possible paths in the network. This technique not only enhances the energy efficiency of each node but also the performance metrics

Miniaturized UWB elliptical patch antenna for skin cancer diagnosis imaging

The biomedical imaging shows promising results in many applications such as protein characterization and cancer detection using non-ionizing radiation. Skin cancer is one of the most common types of cancer because it is exposed by sun rays during the day. Many techniques have been offered to detect the tumor in the early stage such as ultrasonic and MW imaging. However, most of these studies showed a large printing area with lower BW so as the low resolution. To overcome these drawbacks, a new low profile UWB elliptical patch antenna with high performance is designed on PTFE as a substrate. Then a layer of Indium Tin Oxide (ITO) applies to improve the antenna radiation characteristics. The proposed antenna has a broad BW from 3.9 GHz to 30 GHz along with a resonance at 2.4 GHz. Furthermore, the antenna presents a maximum gain of 7.3 dB, maximum directivity of 7.78 dBi, the maximum radiation efficiency of 92 %, and consistent, stable radiation pattern throughout the frequency band. Besides, the time-domain characteristics show that the antenna can be a suitable candidate for microwave imaging of skin cancer

Design of frequency selective limiting circuit

This paper explains the design of frequencyselective limiting circuit. The circuit is typically based on nonlinear matched reflection-mode bandstop resonator. This type of Frequency Selective Limiters achieves fast switching, high-level of power limiting, and flexible channel bandwidth. For single channel limiting, a device with one resonator (first order) produced a band-stop response centred at 2 GHz with 250 MHz of limiting bandwidth, 0 dBm limiting threshold, and 32 dB limiting level and it gave an all-pass response with less than 2.5 dB insertion loss at low RF powers. Multi-resonator filter has been used in order to improve the performance of the device. The prototype will produce intermodulation distortions and response time. Simulated results show an excellent highly selective bandstop performance at high powers with a near all-pass response at low signal powers

Novel Artificial Magnetic Conductor for 5G Application

A design of novel bendable Artificial Magnetic Conductor (AMC) structures has been presented in this paper in two selected of frequencies at 5G application. These designs started with a square patch shape and continued with the combination of circular and Jerusalem shape which resonate at a frequency of 18 GHz and 28 GHz. Details of the theory and the structures of AMCs are explained. The reflection phase, bandwidth, angular stability and dispersion diagram were studied. The simulated results plotted that the novel AMC has good bandwidth and size is reduced by 53 % and 55 % for both frequencies. Other than that, it is also proved that the novel AMC has a stable reflection phase and no band gap performs at the specific frequency. The good performances of this novel AMC make it useful in order to improve antenna’s performanc

Improvement Antenna Performance by using Artificial Magnetic Conductor at 28 GHz

The configurations of single patch antenna integrated with three different designs of patch artificial magnetic conductor (AMC) are presented in this paper in order to investigate the gain, radiation pattern, directivity and bandwidth of the antenna at a frequency of 28 GHz. Three cases of design configuration between patch antenna and three different designs of AMC are analyzed. First, configuration of patch antenna integrated with three designs of patch AMC. Second configuration of patch antenna integrated with non periodic patch AMC and third multilayer patch antenna with patch AMC. The details theory of the design configuration is explained. The simulated reflection coefficient and radiation pattern is presented. The simulated results showed that the gain, directivity and impedance bandwidth of all the design techniques are increased compared to patch antenna without AMC. For the first case, design of patch antenna integrated with design 1 AMC offer 13.96 % bandwidth and 12 % of the gain compared to patch antenna without AMC. In the second case, the overall size is reduced by 9.2 % and 14.14 % , respectively, compared with design in the first case. The third case of design structures provides more gain and bandwidth more than 3.57 %. In addition, the size is reduced compared to the previous two cases. Therefore, the result indicates the capability of this antenna integrated with AMC to be used for future 5G application. Index Terms: Artificia