Numerical analyses of printed line antennas

Square loop, meander dipole and spiral antennas printed on grounded dielectric substrates, are numerically analysed using Sommerfeld type integrals. The square loop is found to have a radiation pattern in which cross-polarisation is negligible and zero in the E-plane and the H-plane, respectively. The results obtained for the meander dipole demonstrate that such an antenna can be made small with no deterioration in the radiation pattern. The analysis of the spiral antenna fed from the outer arms shows that the spiral can radiate a circularly polarised wave with a purely resistive input impedance.<>