REFERENCES

The different impedances needed for the suspended coaxial transmission line can be achieved by varying the size of the centre conductor [15]; here, the size of the outer conductor is fixed. The centre conductor of the resulting suspended coaxial transmission line is shown in Figure 2(a), with the cross-sections of the 50 line and the stubs shown in Figure 2(b). The input and output of the suspended transmission line, as shown in Figure 1, consist of 50 sections of transmission line. For the coaxial assembly shown in Figure 1, layer 3 is 1-mm thick, and layers 2 and 4 are 2.25-mm thick. The complete device has an enclosed overall dimension of 45 20 5.5 mm. The five layers were clamped together for the experimental results given as follows. 3. RESULTS The response of the suspended coaxial transmission line is shown in Figure 3; good agreement between theory and experiment i