A radio frequency, RF, circuit comprising: a first dielectric material (314, 614) having first and second surfaces and a first dielectric constant; a first conductive layer (312, 612) over the first surface of the first dielectric material (314, 614), wherein the first conductive layer (312, 612) includes a plurality of conductive features that include a signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) and a bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859), wherein the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) has a first end and a second end, and the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) has a first section (233, 251, 733, 736, 751, 760, 833, 836, 851, 860) with a first end and a second end; a second conductive layer (316, 616) over the second surface of the first dielectric material (314, 614), wherein a ground plane (215, 715, 815) is formed from the second conductive layer (316, 616), and the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) is formed directly over the ground plane (215, 715, 815), and wherein a conductive material void (234, 252, 734, 737, 752, 761, 834, 837, 852, 861) is present in the second conductive layer (316, 616), wherein the conductive material void (234, 252, 734, 737, 752, 761, 834, 837, 852, 861) is present under the first section (233, 251, 733, 736, 751, 760, 833, 836, 851, 860) of the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) in the second conductive layer (316, 616); and a mounting area (220, 720, 820) for an RF device (270, 770, 870), wherein the first end of the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) and the first end of the first section (233, 251, 733, 736, 751, 760, 833, 836, 851, 860) of the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) are located proximate to the mounting area (220, 720, 820) to enable the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) and the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) to be electrically coupled with one or more leads of the RF device (270, 770, 870) characterized by a second dielectric material (318, 618) over the second conductive layer (316, 616), wherein the second dielectric material (318, 618) has a second dielectric constant that is at least 50 percent less than the first dielectric constant. a first dielectric material (314, 614) having first and second surfaces and a first dielectric constant; a first conductive layer (312, 612) over the first surface of the first dielectric material (314, 614), wherein the first conductive layer (312, 612) includes a plurality of conductive features that include a signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) and a bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859), wherein the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) has a first end and a second end, and the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) has a first section (233, 251, 733, 736, 751, 760, 833, 836, 851, 860) with a first end and a second end; a second conductive layer (316, 616) over the second surface of the first dielectric material (314, 614), wherein a ground plane (215, 715, 815) is formed from the second conductive layer (316, 616), and the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) is formed directly over the ground plane (215, 715, 815), and wherein a conductive material void (234, 252, 734, 737, 752, 761, 834, 837, 852, 861) is present in the second conductive layer (316, 616), wherein the conductive material void (234, 252, 734, 737, 752, 761, 834, 837, 852, 861) is present under the first section (233, 251, 733, 736, 751, 760, 833, 836, 851, 860) of the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) in the second conductive layer (316, 616); and a mounting area (220, 720, 820) for an RF device (270, 770, 870), wherein the first end of the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) and the first end of the first section (233, 251, 733, 736, 751, 760, 833, 836, 851, 860) of the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) are located proximate to the mounting area (220, 720, 820) to enable the signal line (230, 238, 730, 731, 738, 739, 830, 831, 838, 839) and the bias line (232, 250, 732, 735, 750, 759, 832, 835, 850, 859) to be electrically coupled with one or more leads of the RF device (270, 770, 870) characterized by a second dielectric material (318, 618) over the second conductive layer (316, 616), wherein the second dielectric material (318, 618) has a second dielectric constant that is at least 50 percent less than the first dielectric constant.