This paper presents the design of 6dB directional coupler in C-band. A defected ground structure is used underneath the coupled region in order to relax the requirement for a narrow slot between the coupled lines. The simulated results show that the designed coupler exhibits a coupling of 6±0.1dB across the band 4.0 GHz to 4.5 GHz, when the spacing between the coupled lines is larger than 0.1 m...

Mechanical parts such as gears and bearings used in mechanical equipment have a finite lifetime because of corrosion and wear. If the parts are in abnormal operation and is not detected, it may cause catastrophic component failure during operation. One effective approach to detect signs of potential failure of the mechanical equipment is to examine the debris particles in its lubricating oil. T...

An inertia electromagnetic actuator capable of adjusting natural frequency is designed in this paper. There are two procedures in the design of electromagnetic actuator: magnetic circuit design and stiffness conditioning design. ANSOFT software is used to simulate the magnetic circuit during the magnetic circuit design and optimize the design of the actuator. In order to adjust the natural freq...

A compact and simple patch antenna for ultra high frequency band is current demand for RFID tag. By embedding a pair of symmetrical key-shaped slot near the non-radiating edge of the rectangular patch, a new adjacent resonant mode close to the fundamental mode is excited to form a wide half-power impedance bandwidth (Return loss ≥ 3 dB) of 122 MHz to cover the entire frequency range of ultra hi...

Abstract—An ultra wideband (UWB) coplanar waveguide (CPW) fed rectangular monopole antenna, which is of band notched characteristic for Wireless Local Area Network (WLAN), Worldwide inter-operability for Microwave Access (WiMAX) and the C-band satellite communications, is proposed, fabricated and measured. In order to obtain the desired dual band rejections, a piece of pentagonal slotline and a...

This paper presents a compact dual-band printed antenna for 2.4/5.2 GHz WLAN applications. The radiating elements of the proposed antenna are composed of rectangular split-ring elements and metallic loadings placed appropriately between the rings. The antenna size is very compact (22 × 26 × 1.6 mm), and it can be integrated easily with other RF front-end circuits. It is demonstrated that the pr...

AND JEFFREY L. CUTCHER Motorola Inc. Plantation, FL Fractional-N synthesizers are highly desirable in communication systems because of their high frequency resolution output. This resolution is made possible by dithering the divide value using the output of a sigma-delta modulator. A typical sigma-delta fractional-N frequency synthesizer is shown in Figure 1. The tri-state phase frequency detec...

A modified approach for the design of a compact multi-element patch antenna which operates in pentaband is proposed. The antenna comprises of a main patch with subpatches containing resonating slots. The main patch is fed with a 50Ω microstrip line. The antenna operates with multiple operational frequencies covering the bands from 1.9GHz to 9.5GHz with good impedance matching. The design is ver...

A single substrate layer double metallic plane frequency selective surface (FSS) is designed with miniaturized electrical elements and two tunable pass-bands enabling Wireless Local Area Network applications. Each FSS periodic cell consists of a metallic square loop on the top metal layer and its complementary etched on the bottom metal layer separated by a thin dielectric layer. This designed ...

Based on the C-shaped microstrip slot antenna, a new photonic band gap substrate for multifrequency microstrip slot antenna is designed. The antenna has a groove been dug below the radiation plate, within which the radiation plate is placed, and air triangular prism column gaps with different height are placed in the substrate periodically. Numerical simulation is performed for the antenna with...