Microwave switching power divider

A microwave power divider for selectively dividing and switching microwave energy of wavelength .lambda. among a plurality of antenna elements, comprising:

• first and second parallel ground planes shortcircuited along an inner circumference, defining a discoid microwave cavity having an axial height of between 0.05 and 0.1.lambda.,
• a planar dielectric substrate spaced apart between and parallel to said first and second ground planes within and occupying less than five percent of volume of said cavity, said dielectric substrate including microwave power and switching circuits formed on at least one side of said substrate, said circuits comprising:
• a central microwave power distribution element disposed about the center of said substrate and connectable to a source of microwave energy;
• a plurality of power dividing transmission lines lying wholly within said cavity connected to and symmetrically disposed radially about said distribution element, the number of said transmission lines being at least equal to the total number of antenna elements to be switched;
• an equal plurality of output ports equidistantly spaced radially inward from said circumference by a distance of between 0.15 and 0.2.lambda., inclusive, a different one of said ports disposed adjacent and radially outward from a different one of said radial transmission lines;
• and
• an equal plurality of switching means each interposed between a different one of said transmission lines and an adjacent one of said output ports for selectively coupling one or more of said radial transmission lines to corresponding adjacent output ports.

A microwave switching power divider for selectively dividing and switching energy at wavelength .lambda. among a plurality of outputs, comprising:

• first and second parallel circular ground planes joined along an inner circumference, defining a discoid, air loaded microwave cavity having an axial height of between 0.05 and 0.1.lambda.;
• a circular planar dielectric substrate spaced apart midway between and parallel to said first and second ground planes within and occupying less than five percent by volume of said cavity, said substrate having a radius equal to that of said cavity and less than .lambda., said dielectric substrate including identical microwave power distribution and switching circuits formed on opposite sides thereof, each of said circuits including:
• a conductive disk symmetrically disposed about the center of rotation of said dielectric substrate connectable to a source of microwave energy;
• a plurality of tapered power dividing striplines lying wholly within said cavity, symmetrically disposed radially about and connected to said conductive disk, each of said striplines having an increasing width as a function of radial distance from said conductive disk;
• an equal plurality of output ports equidistantly disposed radially outward adjacent different of said radial striplines and radially inward from said circumference by a distance of between 0.15 and 0.2.lambda. inclusive;
• an equal plurality of diode switching means each interposed between the outmost part of different of said striplines and the respective adjacent output port for selectively coupling one or more of said radial stripline to said output ports;
• and
• an equal plurality of microwave blocking chokes each coupled to the outward end of a different one of said diodes and disposed radially outward from the respective transmission line and adjacent output port;
• whereby output impedances for both striplines selectively coupled to output ports and striplines not selectively coupled to output ports are transformed back to said conductive disk with nearly equal transformation ratios.