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Showing posts from December, 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