Image phased and idler frequency controlled mixer formed on an integrated circuit dielectric substrate

For use in a mixer system of the type employing the heterodyne principle of operation by which the combination of an RF input signal and an LO signal generates modulation products including a desired IF signal and an undesired image signal, the combination comprising:

• (a) a dielectric substrate having a layer of conductor material affixed to one face thereof,
• (b) a slot transmission line having a predetermined length formed in said layer of conductor material,
• (c) first and second coplanar strip transmission lines formed in said layer of conductor material and disposed adjacent one and the other ends of said slot line and in longitudinally aligned relationship therewith, said first and second coplanar lines each comprising a center strip of conductor material and one and another longitudinal gaps to one and the other sides of said center strip,
• (d) said one and another longitudinal gaps of the first coplanar line at their ends adjacent the slot line being electrically connected to each other and to the slot line to form a first bifurcated coplanar line-slot line hybrid junction,
• (e) said one and another longitudinal gaps of the second coplanar line at their ends adjacent the slot line being electrically connected to each other and to the slot line to form a second bifurcated coplanar line-slot line hybrid junction,
• (f) means for coupling an RF input signal into said slot line in such manner that the signal propagates in first and second equal components in opposite longitudinal directions along said slot line toward said first and second hybrid junctions respectively,
• (g) first and second pairs of nonlinear devices operatively associated with said first and second hybrid junctions, respectively, said first and second pairs of nonlinear devices each comprising one and another nonlinear device electrically connected across one and the other of the forks of the bifurcated hybrid junction,
• (h) first and second coupling means operatively associated with said first and second coplanar lines, respectively, said first and second coupling means each including a means for coupling the LO signal into the corresponding coplanar line and including a means for coupling the IF signal out from the corresponding coplanar line, and
• (i) said predetermined length of the slot line being so chosen that upon respective injection into the first and second coplanar lines of one and another LO signals which are phase displaced by 90.degree. and upon the resultant respective generation by the first and second pairs of nonlinear devices of one and another image signals which are phase displaced by 180.degree., said slot line will intercouple the first and second pairs of nonlinear devices in a manner which will effectively short circuit the combination of the one and another image signals.

A broadband mixer comprising:

• a first coplanar strip line section;
• a second coplanar strip line section which is longitudinally aligned with said first coplanar strip line section;
• an intermediate slot line section longitudinally aligned with said first and second coplanar line sections and disposed between said first and second coplanar line sections to form first and second hybrid junctions with said first and second coplanar line sections;
• first means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said first coplanar line section to provide a first IF signal;
• second means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said second coplanar line section to provide a second IF signal;
• means for applying an LO input signal to said first and second coplanar line sections, said applying means also conducting the IF signals from the first and second coplanar line sections.

A microwave broadband mixer comprising:

• a first coplanar strip line section having a hybrid junction and a remote end;
• a second coplanar strip line section having a hybrid junction end and a remote end, and longitudinally aligned with said first coplanar line section;
• an intermediate slot line section which is longitudinally aligned with said first and second coplanar line sections and disposed between said first and second coplanar line sections to form first and second hybrid junctions with the hybrid junction ends of said first and second coplanar line sections;
• first means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said first coplanar line section to provide an IF signal, an image signal and a sum signal, said first combining means disposed within said first hybrid junction;
• second means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said second coplanar line section to provide an IF signal, an image signal and a sum signal, said second combining means disposed within said second hybrid junction, the LO input signal provided to said first coplanar line section being out-of-phase with respect to the LO input signal provided to said second coplanar line section such that the image signal of said first combining means is substantially the conjugate of the image signal of said second combining means;
• and
• means for applying an LO input signal to the remote ends of said first and second coplanar line sections, said applying means also conducting the IF signals from the remote ends of said first and second coplanar line sections.

A microwave broadband mixer comprising:

• a first coplanar strip line section having a hybrid junction end and a remote end;
• a second coplanar strip line section having a hybrid junction end and a remote end, and longitudinally aligned with said first coplanar line section;
• an intermediate slot line section which is longitudinally aligned with said first and second coplanar line sections and disposed between said first and second coplanar line sections to form first and second hybrid junctions with the hybrid junction ends of said first and second coplanar line sections;
• first means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said first coplanar line section to provide an IF signal, an image signal and a sum signal, said first combining means disposed within said first hybrid junction;
• and
• second means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said second coplanar line section to provide an IF signal, an image signal and a sum signal, said second combining means disposed within said second hybrid junction, said remote ends of said first and second coplanar line sections being located substantially one-quarter wavelength of the sum signal from the hybrid junction ends of the respective first and second coplanar line sections.

A microwave broadband mixer comprising:

• a first coplanar strip line section having a hybrid junction end and a remote end;
• a second coplanar strip line section having a hybrid junction end and a remote end, and longitudinally aligned with said first coplanar line section;
• an intermediate slot line section which is longitudinally aligned with said first and second coplanar line sections and disposed between said first and second coplanar line sections to form first and second hybrid junctions with the hybrid junction ends of said first and second coplanar line sections;
• first means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said first coplanar line section to provide an IF signal, an image signal and a sum signal, said first combining means disposed within said first hybrid junction;
• and
• second means for non-linearly combining an RF input signal provided to said slot line section with an LO input signal provided to said second coplanar line section to provide an IF signal, an image signal and a sum signal, said second combining means disposed within said second hybrid junction, the longitudinal dimension of one of said first and second coplanar line sections effecting an impedance which is substantially a conjugate match of the impedance characteristic of one of the first and second non-linear combining means such that the impedance of one of the first and second non-linear combining means and the substantially conjugate impedance of one of the first and second coplanar line sections cooperate to present a parallel tuned circuit to the RF input signal for improved efficiency of said mixer.

A microwave, integrated circuit, broadband mixer in which modulation products are produced in accordance with the heterodyne principle, said mixer comprising:

• an integrated circuit, dielectric substrate having a ground plane layer on one side thereof;
• a first coplanar strip line section having a hybrid junction end and a remote end, and having a center strip separated from the ground plane by longitudinally extending gaps between the sides of the center strip and the ground plane layer;
• a second coplanar strip line section having a hybrid junction end and a remote end, and having a center strip separated from the ground plane by longitudinally extending gaps between the sides of the center strip and the ground plane layer, said second coplanar strip line section being longitudinally aligned with said first coplanar strip line section;
• a slot line section which is longitudinally aligned with said first and second coplanar line sections and intermediately disposed between said first and second coplanar line sections such that the first and second coplanar line sections have bilateral symmetry about the transverse axis of the slot line to form first and second hybrid junctions with said first and second coplanar line sections;
• a first diode modulation circuit connected across said first hybrid junction to combine an RF signal with an LO signal to produce an IF signal, an image signal and a sum signal;
• and
• a second diode modulation circuit connected across said second hybrid junction to combine an RF signal with an LO signal to produce an IF signal, an image signal and a sum signal, where said second diode modulation circuit balances said first diode modulation circuit.

A balanced, broadband mixer in which the modulation products of RF and LO signals are produced in accordance with the heterodyne principle, said mixer comprising:

• a first coplanar strip line section having a hybrid junction end and a remote end;
• a second coplanar strip line section having a hybrid junction end and a remote end, and longitudinally aligned with said first coplanar line section;
• an intermediate slot line section which is longitudinally aligned with said first and second coplanar line sections and disposed between said first and second coplanar line sections to form first and second hybrid junctions with the hybrid junction ends of said first and second coplanar line sections;
• first means for non-linearly combining the RF signal provided to said slot line section with the LO input signal provided to the first coplanar line section to generate an IF signal, an image signal, and a sum signal, said first non-linear combining means being disposed across said first hybrid junction;
• second means for non-linearly combining the RF signal which is provided to said slot line section with the LO input signal provided to the second coplanar line section to generate an IF signal, an image signal, and a sum signal, said second non-linear combining means being disposed across said second hybrid junction;
• and
• a bias element for electrically biasing the first and second non-linear combining means to reduce the power requirement of the LO signal.

A microwave, integrated circuit, broadband mixer in which modulation products are produced in accordance with the heterodyne principle, said mixer comprising:

• an integrated circuit, dielectric substrate having a ground plane layer on one side thereof;
• a first coplanar strip line section having a hybrid junction end and a remote end, and having a center strip separated from the ground plane by longitudinally extending gaps between the sides of the center strip and the ground plane layer;
• a second coplanar strip line section having a hybrid junction end and a remote end, and having a center strip separated from the ground plane by longitudinally extending gaps between the sides of the center strip and the ground plane layer, said second coplanar strip line section being longitudinally aligned with said first coplanar strip line section;
• a slot line which is longitudinally aligned with said first and second coplanar line sections and intermediately disposed between said first and second coplanar line sections such that the first and second coplanar line sections have bilateral symmetry about the transverse axis of the slot line to form first and second hybrid junctions with said first and second coplanar line sections;
• a first diode modulation circuit connected across said first hybrid junction to combine an RF signal with an LO signal to produce an IF signal, an image signal and a sum signal;
• a second diode modulation circuit connected across said second hybrid junction to combine an RF signal with an LO signal to produce an IF signal, an image signal and a sum signal;
• and
• a bias element having a predetermined bias potential for forward biasing the first and second modulation circuits to reduce the power requirement of the LO signal, said bias element disposed adjacent to one side of the longitudinally arranged first and second coplanar lines and the slot line such that one edge of the bias element forms one boundary of the slot line and one boundary of a longitudinally extending gap of the first and second coplanar lines, and the other edges of the bias element form one boundary of a perimeter gap between the bias element and the conductor layer to provide electrical isolation of the bias element from the conductor layer.