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.
he Quad Flat No-lead (QFN) package is a CSP (plastic encapsulated package) with a copper lead frame substrate. QFN type package is one of the most cutting-edge IC packaging technologies in the electronics. The QFN is a leadless package where electrical contact to the PCB is made by soldering the leads on the bottom surface of the package to the PCB, instead of the conventional formed perimeter gull wing leads. The QFN-type package is known for its small size, cost-effectiveness and good production yields. QFN also possess certain mechanical advantages for high-speed circuits including improved co-planarity and heat dissipation. The QFN has pins on 4 edges of the bottom surface of the package. The QFN can have either a square or rectangle body as well as symmetric or asymmetric terminal patterns. The QFN was introduced to replace the gull wing lead Quad Flat Package (QFP) because the component leads are embedded in the plastic and cannot be bent during handling to insure consistent ...
RFID stands for Radio-Frequency Identification. The RFID device provides a unique identifier for that object and just as a bar code or magnetic strip the RFID device must be scanned to retrieve the identifying information. More Detail: Microstrip and Printed Antenna Design
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 al...
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