| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of designing a multiband antenna device that allows designing a multiband antenna device having desired characteristics in a short time.SOLUTION: In a first step, the arrangement of a radiation element 11 for low band and a radiation element 12 for high band with respect to a ground conductor 9 is determined, and the electrical length of each part including a radiation element branch circuit is determined. In a second step, a first electrical length between a branch point BP and the radiation element 11 for low band, a second electrical length between the branch point BP and the radiation element 12 for high band, and a third electrical length between the branch point BP and a feeding point FP are defined, and a resonance frequency of low band and resonance and antiresonance frequencies of high band are determined. In a third step, an impedance conversion element 31 for VSWR improvement that is loaded between a feeding circuit 32 and the feeding point FP is defined. |
