Ultra-wideband Circular Antenna Research Articles

Textile UWB 5G Antenna for Human Blood Clot Measurement

The antenna plays an essential role in the medical industry. The short-range 5th Generation (5G) communication can be used for seamless transmission, reception, patient monitoring, sensing and measuring various processes at high speeds. A passive Ultra Wide Band (UWB) antenna, used as a sensor in the measurement of Prothrombin Time (PT) i.e., blood clot is being proposed. The investigated micro-strip patch UWB antenna operating in the frequency range of 3.1 to 10.6 GHz consists of a circular patch with a diamond-shaped slot made of jeans substrate material with good sensing properties is accomplished by adjusting the copper thickness of the patch. Due to the turbidity in blood plasma, PT measurement is the repetitive approach to get accurate value. In order to solve this issue, an antenna is designed, fabricated and analysed to obtain the accurate PT measurements from blood plasma. The blood clotting is observed by electromagnetic emitted voltage converted into the frequency range of 5 to 10 GHz and voltage range of 0.66 to 0.87 mV. The circular UWB antenna is constructed employing jean’s substrate with a partial ground plane to improve the S-parameter, gain, bandwidth and performance characteristics. The proposed antenna with Specific Absorption Rate (SAR) value within the acceptable range can be used as a wearable device in the human body, leveraging 5G technology. This antenna is well suited for various other applications like wireless sensors, wearable devices and short-range communication applications.

Design of Dual-Band Notched UWB Antenna Loaded with Split Ring Resonators for Wide Band Rejection

ABSTRACT Nowadays, the design of a miniaturised ultra-wideband (UWB) antenna with wide dual band-notched characteristics gained widespread demand in wireless communications to reduce interference. The design of a planar CPW-fed circular UWB antenna loaded with split ring resonators and stubs is presented to eliminate two frequency bands. Two symmetrical circular split ring resonators are etched below the CPW feed at the backside of a circular UWB monopole antenna to suppress 3.61 GHz–5.57 GHz (sub-6 GHz band) wideband interference, whereas the 7.06 GHz–8.79 GHz (X-band uplinks and downlinks) band is suppressed by loading two L-shaped stubs. Slots are also made on the patch and ground to enhance impedance matching at a lower resonance frequency. The proposed notch band antenna has a compact size of 38 × 32 × 1.6 mm3 and has the highest gain of 5.75 dB at a frequency of 9 GHz. The parametric analysis has been performed to obtain optimised dimensions for better performance. The designed antenna is simulated, prototyped and tested to validate the antenna design.

A miniaturized slotted ground structure UWB antenna for multiband applications

AbstractA concept of using slots both in the radiator and in the ground to miniaturize an ultrawideband (UWB) antenna in order to operate at multiband is demonstrated. Initially, a miniaturized circular UWB antenna is designed which results in about 53.5% reduction in total volume and about 46.6% in the active patch area, in comparison to the conventional UWB antenna. To reconfigure the proposed UWB antenna to operate in multiband applications, slotted ground approach is used. The slots in the ground plane of the proposed design affects the surface current distribution due to which the designed antenna operates at 3.7 (middle WiMAX), 5.7 (upper WiMAX), and 7.5 GHz (X‐band) with −10 dB reflection coefficient bandwidth of about 5.3% (3.64–3.84 GHz), 5.5% (5.64–5.96 GHz), and 3.7% (7.44–7.72 GHz), respectively. The proposed configuration is compact in size with a total area of only 0.26λ0 × 0.21λ0 = 30 × 24.8 = 283.3 at lower resonating band of 2.6 GHz. The designed multiband structure yields good impedance matching, acceptable gain and stable radiation characteristics both in xz and yz plane, across their operational bandwidths.

A Modified Compact Ultra Wideband Antenna with Band Rejection for WLAN Applications

In this paper, a circular ultra wideband antenna is considered which comprises of a planar circular patch element on grounded FR4 substrate of 1.6 mm thickness generating the bandwidth of 6.8 GHz. To enable its extensive use in Wireless Local Area Network (WLAN) applications, it is modified by modulating the microstrip line to generate stopband from 5.9 to 9 GHz rejecting the extended C band and X band. The antenna ground plane is then drilled to form holes implementing EBG structures to obtain desired passband characteristics, from 1.97 to 2.65 GHz and 3.12 to 5.86 GHz suitable for WLAN(2.40–2.484/5.150–5.350/5.725–5.825 GHz) applications. The designed antenna shows good passband and stopband characteristics and return loss S11 and nearly omni-directional field pattern over the frequency band of the passband.

Multiobjective Synthesis of Steerable UWB Circular Antenna Array considering Energy Patterns

True-time delay antenna arrays have gained a prominent attention in ultrawideband (UWB) applications such as directional communications and radar. This paper presents the design of steerable UWB circular array by using a multiobjective time-domain synthesis of energy pattern for circular antenna arrays. By this way we avoid individual beamforming for each frequency in UWB spectrum if the problem was addressed from the frequency domain. In order to obtain an energy pattern with low side lobe level and a desired main beam, the synthesis presented is performed by optimizing the true-time delays and amplitude coefficients for the antenna elements in a circular geometry. The method of Differential Evolution for Multiobjective Optimization (DEMO) is used as the optimization algorithm in this work. This design of steerable UWB circular arrays considers the optimization of the true-time exciting delays and the amplitude coefficients across the antenna elements to operate with optimal performance in the whole azimuth plane (360°). A comparative analysis of the performance of the optimized design with the case of conventional progressive delay excitations is achieved. The provided results show a good performance for energy patterns and for their respective power patterns in the UWB spectrum.