293. increase bandwidth even further, by increasing the eﬀective height of the structure and by
creating a double-tuned resonance eﬀect .
A CAD formula for the bandwidth (deﬁned by SWR 2.0) is
p tan þ
where the terms have been deﬁned in the previous section on radiation eﬃciency. The
result should be multiplied by 100 to get percent bandwidth. Note that neglecting
conductor and dielectric loss yields a bandwidth that is proportional to the substrate
Figure 9.6 shows calculated and measured bandwidth for the same patch in Fig. 9.5.
It is seen that bandwidth is improved b