Fractal Bowtie Antenna Research Articles

A miniaturized 2-itertion rectangular slotted Sierpinski Fractal Bowtie antenna for multiband applications

Recent advancements in the field of Telecommunications and wireless technology services need compact, multiband antennas with reduced system complexity. In this paper a novel Rectangular slotted Sierpinski Fractal Bowtie antenna is illustrated and is further expanded up to 2-iterations to obtain multi frequency bands with increased percentage of Miniaturization. The overall volume of the proposed 2-iteration SPK Bowtie antenna is (50 × 50 × 1.6) mm3 and the substrate is FR-4 epoxy with 4.4 dielectric constant. All the 0th, 1st and 2nd iterations of Rectangular slotted SPK Fractal Bowtie antenna are exited with coaxial probe feed and are simulated using ANSYS HFSS software for 100 MHz to 14 GHz frequency range. The radiation parameters like return loss, Bandwidth, VSWR, and Gain are evaluated and compared. The simulation results shows that proposed 2nd iteration Rectangular slotted SPK Fractal Bowtie antenna exhibits more number of frequency bands as compared to the 0th and 1st iterations. The proposed design is able to resonate at frequencies 0.2 GHz, 3.5 GHz, 6.3 GHz, 8.6 GHz, 10.9 GHz, 11.7 GHz with a gain of 0.529 dB, 5.074 dB, 4.518 dB, 5.335 dB, 9.18 dB, 21.17 dB respectively. The percentage of Miniaturization is also increased to 58.2% in the case of 2-iteraion. A prototype of the final proposed antenna is fabricated and tested using VNA network analyzer. The fabricated prototype of proposed antenna is also capable of resonating in L, C, S, and X bands. The simulated results of the proposed antenna have a great matching with the measured results.

New Movable Plate for Efficient Millimeter Wave Vertical on-Chip Antenna

A new movable plate concept is presented in this paper to realize mm-wave vertical on-chip antennas through MEMS based post-processing steps in a CMOS compatible process. By virtue of its vertical position, the antenna is isolated from the lossy Si substrate and hence performs with a better efficiency as compared to the horizontal position. In addition, the movable plate concept enables polarization diversity by providing both horizontal and vertical polarizations on the same chip. Through a first iteration fractal bowtie antenna design, dual band (60 and 77 GHz) operation is demonstrated in both horizontal and vertical positions without any change in dimensions or use of switches for two different mediums (Si and air). To support the movable plate concept, the transmission line and antenna are designed on a flexible polyamide, where the former has been optimized to operate in the bent position. The design is highly suitable for compact, low cost and efficient SoC solutions.

Nano-antennas for optoelectronics and nanophotonics

The evolution of the design of radio and microwave antennas has allowed new, diverse, and ubiquitous applications of great added value, ranging from global positioning systems to cellular-phone networks. Scaling these designs down towards optical wavelengths has faced two main practical restrictions. On one hand, until recently there have been technological and fabrication issues. On the other, they could not compete against the prevailing semiconductor-based emitters (light-emitting diodes, laser diodes) and detectors (PIN detectors, avalanche photo diodes, etc.). It is now a time of new opportunity for optical or nano-antennas. An optical antenna, also called an antenna-coupled optical detector, is the marriage of two clearly distinguishable elements working conjointly: a metallic antenna structure that collects the optical radiation, and a transducer that turns the received power into an electric signal. Each of these elements can be optimized for a given application. Nano-antennas are the smallest detectors available, scaled to a fraction of the received wavelength. By nature they are direction, wavelength-, and polarization-sensitive elements. The transduction mechanism has a potential response time in the order of tens of femtoseconds. Optical antennas have the advantage that they are integrable with diffractive and conventional optical elements, waveguides, and read-out electronics, and they work at room temperature. A comparison of the performance of these devices with other detectors is shown in Figure 1. Based on this analysis, optical antennas are set to detect light in polarimetric imaging systems, multiband and multispectral applications from the visible to the millimeter-wave bands (see Figure 1. This fractal bow-tie antenna array is designed to detect five bands centered at wavelengths of λ0, 2λ0, 4λ0, 8λ0, and 16λ0.