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Showing posts from 2016

EMI & EMC Compliance of Smartphone

EMC within electronic components has become an increasingly important issue for embedded designers to contend with. As system frequencies and the need for lower supply voltages increase, the end application becomes more and more vulnerable to the negative affects of EMI. These electrical influences can be generated by either radiated or conductive EMI sources. Radiated sources include anything electrical or electromechanical, including motors, power lines, antennas, traces on a PCB (Printed Circuit Board), and even the silicon components on the PCB. Conductive EMI primarily shows itself as electrical “noise” on the power supply lines of an application and can be caused by induced voltage spikes from other devices within a system. Electromagnetic Interference (EMI): Electromagnetic emissions from a device or system that  interfere with the normal operation of another device or system. EMI is also referred to as Radio Frequency Interference (RFI) Electromagnetic Compatibility (E

Dual Channel Rotary Joint

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A Rotary Joint (RJ) is a wide spread microwave device that is used to change the direction of microwave propagation between two waveguides by rotating one with respect to another. Rotary joints find many applications in radar and satellite earth stations for functions such as polarization rotation; antenna feed systems and azimuth and elevation motions. Many styles of rotary joints are available for a variety of environmental conditions. Multichannel rotary joints must be carefully designed to achieve low channel loss and small rotational variations of this loss.   A n investigation was first carried out to review the state of the art in the field of multiple-channel rotary joints and to select the types of propagation modes that best satisfied the special system needs. A review of possible design approaches led to the selection of a concentric coaxial line configuration for the main body of the rotary joint, with integral transitions to waveguide at both ends for minimum over
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Slotted Waveguide Array Antenna Slotted antenna arrays used with waveguides are a popular antenna in navigation, radar, and other high-frequency systems. A waveguide is a very low loss transmission line. It allows propagating signals to a number of smaller antennas (slots). Each of these slots allows a little of the energy to radiate. Slot impedance and resonant behavior for a single slot are dependent on slot placement and size. Its exceptional directivity in the elevation plane gives it quite high power gain. The slotted waveguide has achieved most of its success when used in an omnidirectional role To make the unidirectional antenna radiate over the entire 360 degrees of azimuth, the second set of slots are cut on the back face of the waveguide. An 8×8 planar four pole X-band Tchebyshev dual inductive post substrate integrated waveguide filter from 10.15 GHz to 10.7 GHz is designed for terrestrial broadcasting. The filter is designed on the 5870 with a relative dielectric

5G Beam Forming Network

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Array Antenna Feed Networks There is various kind of feeding network of an array antenna. Feed network depend on antenna type and geometry. Feed network for microwave applications is a major design concern in terms of complexity and size.
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DESIGN OF PLANAR ANTENNAS FOR WIRELESS APPLICATIONS Planar antennas, including microstrip and printed antennas, metal-plate antennas, ceramic chip and dielectric resonator antennas have a low profile hence, these antennas have extensive applications in mobile systems (such as 900/1800 MHz bands), wireless local area networks (WLANs, such as 2.4/5.2/5.8 GHz bands), ultra-wideband (UWB, such as 3.1 ~ 10.6 GHz band) communications. Wireless antennas are used in GSM, WLAN, MAN, CDMA, Wireless Routers, Mobile Handsets, PDA. We can divide these into 3 main categories. Internal dual-/multi-band mobile phone antennas including PIFAs, very-low-profile monopoles, printed loop antennas, printed slot antennas for mobile phones, PDA or smart phones WLAN mobile-unit antennas, including dual-band and/or diversity operations and the antenna mountable above the system, ground plane of the mobile unit UWB antennas for mobile units and access points, including the design techniques for UWB

SIW (Substrate Integrated Waveguide) Patch Antena

SIW technology is essentially a hybrid of microstrip and dielectric-filled waveguide (DFW) technologies. Starting with a PCB substrate, top and bottom metal layers provide two of the waveguide walls. Then, two parallel rows of vias are added, forming the side walls of the waveguide. Figure 1 shows a microwave filter constructed using SIW technology. The SIW technology for passive circuit design has been  implemented for its low cost, compact topology and high performance. There has been increasing interest in implementing SIW technology in active circuits and complete systems, including active integrated antennas.
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Higher ORDER MODE ANALYSIS USING FINITE DIFFERENCE Coaxial waveguides and the determination of their cutoff frequencies have been discussed by Marcuvitz . This involves finding zeros of a function that involve products of Bessel functions of 1 st  kind and 2 nd  kind for TM modes and products of derivatives of Bessel functions of 1 st  kind and 2 nd  kind for TE modes. These zeros pertain to a certain order and need a number of iterations to be performed to obtain a set of cutoff wavenumbers. Finite difference methods in the conventional form have been applied t0 a variety of cross sections. However, the same technique involving the formation of rectangular meshes to a circular coaxial waveguide does not seem to be appealing in context with the selection of truncation boundaries and appropriate adjacent node points for the region between the inner and outer conductors. The increase in the number of spurious modes generated and the decrease in accuracy are also detrimental to t

4-Channel Transmit Module with Patch Antenna for 5G Application

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MODELING AND SIMULATION OF CHAFF CLOUD Chaff finds are mainly used in electromagnetic countermeasures. A cloud of chaff is an artificial target made up of a bunch of small thin metallized glass fiber or wire. Chaff consists of thin dipole elements cut to resonate at radar frequencies. Chaff Clouds are dispensed in the air through the chaff cartridge on aircrafts . Chaff Cloud masks the real target return signal therefore, the detection of target become more complicated. The reflected signal from the chaff cloud disturbs the opponent’s radar system and creates a false signature in the enemy radar. Because of high RCS signature, after launching a chaff cloud, the incoming missile tends to track on the chaff. The aircraft can then perform a fast, sharp maneuver, deviating from the missile path. Radar Cross Section (RCS) is defined as the area a target would have to occupy to produce the amount of reflected power that is detected back at the radar, and is classified according
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Signal Integrity Analysis of High-Speed Interconnects Signal integrity (SI) addresses two key aspects in high-speed digital designs: signal timing and quality. SI analysis aims to ensure signals reach their destination in good condition. In a system, signals travel through various kinds of interconnections (e.g., from chip to package, package to RF board trace and trace to high-speed connectors), with any electrical impact happening at the source end, along with the transmission path or at the receiving end, which affects both signal timing and quality. Connector performance directly affects system performance and reliability. As a result, designing and modeling connectors for multi-gigabit applications is one of the greatest challenges in high-speed digital applications. When designing high-speed applications, the signal transmission quality is a critical factor. At gigabit speeds, high-speed interconnects must be characterized along with the RF board traces. The ever-increa