**Author details**

1

142 Advanced Electromagnetic Waves

−22 −20 −18 −16 −14 −12 −10 −8 −6 −4 −2 0

**5. Conclusion**

Magnitude S (dB)

2 4

<sup>7</sup> 7.2 7.4 7.6 7.8 <sup>8</sup> 8.2 8.4 8.6 8.8 <sup>9</sup> 9.2 9.4 −24

(a)

Frequency (GHz)

reflection coefficients and coupling between neighboring ports

measurements well agree with the results of simulation.

3

**Figure 30.** Photograph of fabricated four-port CFCL circulator: (a) top view and (b) bottom view

S32 S13 S41 S24 S23 S31 S14 S42 −22 −20 −18 −16 −14 −12 −10 −8 −6 −4 −2 0

**Figure 31.** Measured scattering parameters of four-port CFCL circulator: (a) transmission with isolation and (b)

and a lower level of isolation with respect to simulated results at port (2) result from the inaccuracy of manufacturing process due to technological limitations. The greatest impact on the deterioration of the device parameters had the positioning of the cylindrical ferrite coupled line section with respect to planar structures. Nevertheless, the obtained results of

In this chapter, the research on nonreciprocal devices utilizing longitudinally magnetized ferrite coupled lines junction is presented. The different configurations of FCL junctions were taken into account, comprising planar lines and conformal guides realized as striplines or slotlines placed on cylinder with circular cross section. The description of developed fast and efficient hybrid methods for the analysis of investigated FCL junctions was presented. The numerical results for planar and conformal FCL junctions were calculated and shown. Finally, the numerical and experimental results concerning nonreciprocal devices utilizing

proposed planar and conformal FCL junctions were presented and discussed.

Magnitude S (dB)

<sup>7</sup> 7.2 7.4 7.6 7.8 <sup>8</sup> 8.2 8.4 8.6 8.8 <sup>9</sup> 9.2 9.4 −24

(b)

Frequency (GHz)

S11 S22 S33 S44 S34 S43 S12 S21

(a) (b)

Adam Kusiek∗, Wojciech Marynowski, Rafal Lech and Jerzy Mazur

\*Address all correspondance to: adakus@eti.pg.gda.pl

Gdansk University of Technology, Faculty of Electronics, Telecommunications and Informatics, Poland
