Radiation characteristics of a transmission line with a side plate

Abstract

SUMMARYAs a structure that reduces radiation from a transmission line with input and output ports, a transmission line with a side plate is proposed in this paper. The radiation field by the traveling wave current on the transmission line is derived and the radiated power is analytically derived. From this analysis, it is found that in order to reduce radiation loss, (1) the transmission line height should be reduced, (2) the characteristic impedance be increased, (3) the propagation constant of the current be increased, and (4) the distance to the side plate be reduced. Further, a transmission line with a side plate is fabricated and the effect of radiation reduction is compared with the theoretical result and demonstrates the validity of the paper.

Radiation from quasi‐TEM insulated transmission lines

“…In [5] they did not obtain analytic expression for the radiation as function of TL length, but they did obtain analytic expressions for the long TL limit, with which we compare here our results. Eq.…”

“…Next we compare the radiation patterns obtained in Figure 5 of [5], with ours. In [3] we compared the free space case in panel (a), and here we compare our result (Eq.…”

“…al. published the paper "Radiation Characteristics of a Transmission Line with a Side Plate" [5] which intends to reduce radiation losses from TLs using a side plate. The side plate is a perfect conductor put aside the transmission line, to create opposite image currents, and hence reduce the radiation.…”

“…Therefore for the sake of comparison with [5] we have to use ǫ p = 1, hence n = n eq in all our results.…”

“…which is exactly what they called "the radiated power from the input end (or output end) alone", given in Eq. (30) in [5] (note that they used the distance between conductors 2h, corresponding to our d, from there the factor 4). Also note that the limit of Z in Eq.…”