Microstrip Line Loss Of Theoretical Research And Engineering Applications

The rapid development of wireless communication technology has excited the developing tendency of compactness, miniaturization and integration for the microwave radio frequency circuits. As one of the main transmission lines of MMIC, the microstrip lines have received a lot of attentions. The researches of microstrip lines are mainly focused on engineering design and losses. As we all know, the losses of microstrip lines mainly include dielectric loss, conductor loss and radiation loss.In the low frequency miniature microstrip circuits, the loss may be negligible. However, as frequency and circuit scale increase, the total loss accumulated in the large-scale circuits becomes bigger, which will affect the performance of the microstrip circuits, especially in millimeter wave. In this way, it is thus impossible to neglect the losses. Currently, looking-up table and approximate estimation are the main methods to calculate the losses of microstrip, however, they are a little complicated and the accuracy is not high enough. In this paper, some researches have been carried out, including the formula derivation and verification for conductor loss and dielectric loss in microstrip lines. The comparisons between theoretical calculation and software simulations indicate the high accuracy of our formulas. These will provide some useful guides for engineering design of low-loss microstrip circuits. In addition, a compact four-way Wilkinson power divider is designed to demonstrate the compact design of microstrip circuits.