Analysis of arbitrary shaped microstrip circuits and antennas on finite substrates

An integral equation technique is presented for the analysis of arbitrary shaped printed circuits and antennas on a finite substrates. The integral equation is formulated in the space domain with triangular basis functions so that any arbitrary shaped structures may be modelled. Both the dielectric layers and the ground planes are considered to be finite. When the dielectric structure and the ground plane is infinite a Sommerfeld-type of space domain Green´s function is used to solve for the currents on the printed circuits. When the dielectric layers and the ground plane are finite, the equivalence principle has been used to replace the dielectric layers and the ground planes and the free space Green´s function has been utilized.