2. Antenna aperture
• It can be visualized as the area of a circle
constructed broadside to incoming radiation
where all radiation passing within the circle is
delivered by the antenna to a matched load.
• The incoming power density x aperture = available power from
antenna
3. Aperture antenna -Types
• Parabolic reflector antenna
• Horn antenna
• Cassegrain antenna
• Lens antenna
• Applications
– Useful for aircraft and spacecraft applications
bcoz very conveniently mounted on the skin of
the aircraft or spacecraft
4. Aperture antennas
• Asymmetrical gain patterns can be achieved by
using asymmetrical apertures or illumination
function.
• Tapering the aperture illumination reduces side
lobe levels at the expense of mainlobe broadening
and gain (efficiency) reduction.
• There is a Fourier transform relationship b/w the
aperture illumination Taper function and radiation
pattern
