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 impedance matching, improved Omni-directionality in the azimuthal radiation, pattern stability, polarization purity and band-notching.
Necessary Steps to Design Wireless Antenna
First of all figure out wireless domain like GPS, DCS-1800, IMT-2000, WLAN Applications, Bluetooth…..
Next steps are finding out major specification of antenna
Resonating Frequency of antenna
Antenna Gain requirement
Choose a suitable substrate , it may depend upon various factor like availability of material, integration of antenna with other circuit components on board. Dielectric constant and height of substrate are important for microstrip antenna parameter calculation
Calculate Microstrip antenna dimension. Most of the time antenna used in wireless communication are not a simple antenna, these are customized structure.
Draw substrate and antenna geometry, define materials