Singly fed circularly polarized microstrip antenna

Claim 2

A singly fed circularly polarized microstrip antenna comprising: a dielectric substrate; a conducting ground layer coated on one side of said dielectric substrate; and a conducting patch radiator coated on the other side of said dielectric substrate, the radiator having a feed point (x c , y c ) which is a solution of the following equation ##EQU17## where ν, ν+1 represent two orthogonal modes contributing a circularly polarized wave; ψ.sup.(ν) represents an eigenfunction with respect to a ν-th mode determined by the dimensions of the radiator and which is a function with respect to the position (x, y); E 0 .sup.(ν) (0, ω c ) represents an electric field in a direction θ=0° with respect to the ν-th mode; C represents a capacitance component of an equivalent circuit parameter for a microstrip antenna; L.sup.(ν) represents an inductance component of an equivalent circuit parameter for a microstrip antenna; and ω c is an exciting frequency which is a (μ+1)-th solution of the following interative equation: ##EQU18## g.sup.(ν) (ω): a conductance component of an equivalent circuit parameter for a microstrip antenna, which is a function with respect to ω.

Claim 3

A singly fed circularly polarized microstrip antenna according to claim 1, in which said radiator has a linearly symmetrical configuration and a feed point is located on other than two straight lines intersected at an angle of ±45° with respect to a symmetrical axis and at an equidistant point of the symmetrical axis.

Claim 4

A singly fed circularly polarized microstrip antenna according to claim 2, in which said feed point is a point of loci determined according to an exciting frequency and the rotational direction of circularly polarized waves.

Claim 5

A singly fed circularly polarized microstrip antenna according to claim 3, in which said radiator has a substantially square configuration of a×b where a≠b but a≃b and can excite circularly polarized waves at two different frequencies, the loci of said feed point are in the vicinity of vertical bisecting lines drawn with respect to each side of the configuration, and the loci for right-hand and left-hand rotation circularly polarized waves at the respective frequencies are substantially symmetric with the vertical bisecting line as a center.

Claim 6

A singly fed circularly polarized microstrip antenna according to claim 3, in which said radiator has a pentagonal configuration and can excite circularly polarized waves at two different frequencies and the loci of the feed point are located on four curves which are symmetrical with respect to a symmetrical axis of the pentagonal.

Claim 7

A singly fed microstrip antenna according to claim 3, in which said radiator has an isosceles triangle configuration and can excite circularly polarized waves at two different frequencies, and the loci of the feed point are located on four curves which are symmetrical with respect to a symmetrical axis of the isosceles triangle.

Claim 8

A singly fed circlarly polarized microstrip antenna comprising: a dielectric substrate; a conducting ground layer coated on one side of said dielectric substrate; and a radiator array comprised of a plurality of conducting patch radiators, having the same shape, coated on the other side of said dielectric substrate, the radiators having the same feed point (x c , y c ) which is a solution of the following equation ##EQU19## where ν, ν+1 represent two orthogonal modes contributing a circularly polarized wave; ψ.sup.(ν) represents an eigenfunction with respect to a ν-th mode determined by the dimensions of the radiator and which is a function with respect to the position (x, y); E 0 .sup.(ν) (0, ω c ) represents an electric field in a direction θ=0° with respect to the ν-th mode; C represents a capacitance component of an equivalent circuit parameter for a microstrip antenna; L.sup.(ν) represents an inductance component of an equivalent circuit parameter for a microstrip antenna; and ω c is an exciting frequency which is a (μ+1)-th solution of the following interative equation: ##EQU20## g.sup.(ν) (ω): a conductance component of an equivalent circuit parameter for a microstrip antenna, which is a function with respect to ω.

Claim 9

A singly fed circlarly polarized microstrip antenna comprising: a dielectric substrate; a conducting ground layer coated on one side of said dielectric substrate; and a radiator array comprised of a plurality of conducting patch radiators, having the same shape, coated on the other side of said dielectric substrate, the radiators having the same feed point (x c , y c ) which is a solution of the following equation ##EQU19## where ν, ν+1 represent two orthogonal modes contributing a circularly polarized wave; ψ.sup.(ν) represents an eigenfunction with respect to a ν-th mode determined by the dimensions of the radiator and which is a function with respect to the position (x, y); E 0 .sup.(ν) (0, ω c ) represents an electric field in a direction θ=0° with respect to the ν-th mode; C represents a capacitance component of an equivalent circuit parameter for a microstrip antenna; L.sup.(ν) represents an inductance component of an equivalent circuit parameter for a microstrip antenna; and ω c is an exciting frequency which is a (μ+1)-th solution of the following interative equation: ##EQU20## g.sup.(ν) (ω): a conductance component of an equivalent circuit parameter for a microstrip antenna, which is a function with respect to ω.

Claim 10

A singly fed circularly polarized microstrip antenna comprising: a dielectric substrate; a conducting ground layer coated on one side of said dielectric substrate; and a radiator array comprised of a plurality of conducting patch radiators, having the same shape, coated on the other side of said dielectric substrate, some radiators having a feed point (x c , y c ) which is one of solutions of the following equation, the other radiators having a feed point (x c , y c ) which is the other solution of the following equation ##EQU21## where ν, ν+1 represent two orthogonal modes contributing a circularly polarized wave; ψ.sup.(ν) represents an eigenfunction with respect to a ν-th mode determined by the dimensions of the radiator and which is a function with respect to the position (x, y); E 0 .sup.(ν) (0, ω c ) represents an electric field in a direction θ=0° with respect to the ν-th mode; C represents a capacitance component of an equivalent circuit parameter for a microstrip antenna; L.sup.(ν) represents an inductance component of an equivalent circuit parameter for a microstrip antenna; and ω c is an exciting frequency which is a (μ+1)-th solution of the following interative equation: ##EQU22## g.sup.(ν) (ω): a conductance component of an equivalent circuit parameter for a microstrip antenna, which is a function with respect to ω.

Claim 11

A singly fed circularly polarized microstrip antenna comprising: a dielectric substrate; a conducting ground layer coated on one side of said dielectric substrate; and a radiator array comprised of a plurality of conducting patch radiators, having the same shape, coated on the other side of said dielectric substrate, some radiators having a feed point (x c , y c ) which is one of solutions of the following equation, the other radiators having a feed point (x c , y c ) which is the other solution of the following equation ##EQU21## where ν, ν+1 represent two orthogonal modes contributing a circularly polarized wave; ψ.sup.(ν) represents an eigenfunction with respect to a ν-th mode determined by the dimensions of the radiator and which is a function with respect to the position (x, y); E 0 .sup.(ν) (0, ω c ) represents an electric field in a direction θ=0° with respect to the ν-th mode; C represents a capacitance component of an equivalent circuit parameter for a microstrip antenna; L.sup.(ν) represents an inductance component of an equivalent circuit parameter for a microstrip antenna; and ω c is an exciting frequency which is a (μ+1)-th solution of the following interative equation: ##EQU22## g.sup.(ν) (ω): a conductance component of an equivalent circuit parameter for a microstrip antenna, which is a function with respect to ω.