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In this letter, a compact multi‐band reconfigurable CPW fed bowtie slot antenna is presented and these performances are discussed. The known properties of the bowtie antenna, namely a high gain and a fairly large bandwidth have been used in order to design a reconfigurable multiband antenna which makes it possible to switch between a single band (initial mode) and dual band or triple band modes, making it more agile in frequency. The proposed approach is based on the integration of two pairs of slots on the two sides of the antenna to create new bands optimized to operate in the two bands of WiFi and WiMAX at 2.4 GHz and 3.5 GHz, respectively. The results of measurements and simulations are presented and compared and a good agreement is established. The antenna is intended for multiservices and cognitive radios applications.

This paper presents a frequency bandwidth reconfigurable antenna capable of gradually varying its bandwidth from 43 to 76% by keeping the lower band limit fixed and varying the upper one. The antenna consists of a disc‐monopole antenna with four vertical slot lines and a via‐shorted slot ring incorporated in its ground‐plane. To vary the bandwidth, the first slot line is used to create a new resonance below the operating band of the monopole, which is used as the fixed lower band limit. The next two slots are used to vary the upper limit while adjusting the middle resonance in order to maintain a good impedance‐matching over the bandwidth. The fourth slot line and the shorted slot ring are used together to suppress high frequencies. In addition to this gradual bandwidth reconfiguration, the proposed antenna has the potential to offer several different modes of operation; however for concise reasons, only two other modes corresponding to a single‐band and a dual‐band narrowband, modes are presented here. To validate the proposed bandwidth reconfiguration approach, simulated and measured results are provided and a good agreement is achieved. The antenna is potentially suitable for applications needing to adjust the frequency bandwidth such as cognitive radios.

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A miniature frequency bandwidth reconfigurable antenna is presented. Four slots and a ring slot resonator are integrated to the ground plane of an UWB antenna in order to achieve frequency reconfiguration, maintaining the original size unchanged. The proposed antenna is capable of adjusting both the frequency and the bandwidth by using switches to control the electrical length of the slots, offering thus pre-filtering functionality. Antenna performance obtained from simulation and measurement results shows a fair agreement, which validates the proposed design approach. The antenna is potentially suitable for wireless communication and cognitive radio.

Simultaneous localization and mapping is very essential for autonomous navigation when the mobile robot is navigating in unknown environment without a global positioning system. Various techniques to solve the simultaneous localization and mapping problem have been extensively studied using the combination of low-cost sensors. Most of the work in mobile robotics still consists of finding solutions to problems in data exchange between mobile robot and communication control station, which is a challenging task. In fact, communication systems impose severe constraints in terms of channel capacity and transmission quality, because the transmission channel in communication systems is undergoing at the different physical phenomena like scattering, diffusion and diffraction, which occur interference and multiple path effects in wireless communications, while keeping these effects levels low. This article describes a simultaneous localization and mapping problem based on second-order smooth variable structure filter embedded in mobile robot equipped with a sensor for data wireless collection. The inclusion of the control in environments outside the mobile robot field of view can make the wireless communication simultaneous localization and mapping process much more difficult to find a solution under realistic conditions. In order to solve the simultaneous localization and mapping issue and to mitigate the fading phenomena, which affect the quality of service in advanced wireless communication systems, we use a new approach to combat the fading effect without requiring any statistical knowledge of the propagation channel parameters. Several experiments have been done in real-world applications, and good performances were obtained using a second-order smooth variable structure filter–simultaneous localization and mapping algorithm–based wireless communication.

An UWB to four sub-bands frequency reconfigurable CPW-fed disc monopole antenna is presented. A single pair of ring slot resonators is inserted to the CPW ground plane to achieve the reconfiguration, maintaining the original size unchanged. The proposed antenna is capable of switching between a wide operating band of 2.3 GHz -10.5 GHz and four different sub-bands, offering pre-filtering functionality to the system. Switches were employed at specific locations in the resonator to change its effective electrical length, hence forming different filter configurations. Antenna performances obtained from simulation and measurement results show a good agreement, which validates the proposed design approach. The antenna is potentially suitable for applications requiring dynamic band switching such as cognitive radios.

This paper describes the design guidelines for frequency independent 180° phase shifters. The proposed configuration is based on microstrip slot transition technique. The frequency independence feature is due to comparing two quasi‐identical structures and the phase inversion (180°) is related to the chosen inverted orientation of the main line compared to the reference one. Moreover, two different schemes are designed and manufactured and a good simulation to measurement agreement is demonstrated. Thus, interesting results are obtained (more than 10 dB return loss, less than 2.1 dB insertion loss and less than ± 3.6° phase deviation).