**4. Conclusions**

We show the measured versus simulated return loss and realized gain of the dual-band antenna at S-band in **Figures 8** and **9** as well as at X-band in **Figures 10** and **11**. We took all realized gain versus frequency measurements at boresight to the antenna. We see general agreement at both bands for all measurements. One

*Advanced Radio Frequency Antennas for Modern Communication and Medical Systems*

**Figure 8.**

**Figure 9.**

**Figure 10.**

**196**

*S-parameters at S-band horizontal polarization port.*

*Realized gain to boresight at S-band horizontal polarization port.*

*S-parameters at X-band horizontal polarization port.*

This chapter describes both the benefits and current challenges facing AM for antennas and RF devices. The forefront of which is a lack of commercially available high-dielectric materials that are compatible with filament fed 3D printers. As a comparison, we fabricated two similar antenna designs utilizing multiple nested dielectrics and an embedded shorting wall within the dielectrics to compare performance between traditional materials and manufacturing methods versus those of AM. Due to restricted access to an AM feedstock with the proper dielectric constant, direct comparisons of the two antennas is not the preferred way of comparison. However, experimental results for both prototypes agree well with the simulation data. There also seems to be no degradation in the performance of the AM prototype over the traditional prototype in terms of the agreement with the respective antenna models. With new methods of extruding higher dielectric filaments for FDM 3D printers, AM seems to be a good fit for future work in antenna design especially as antenna and RF front ends grow increasingly complex and more fully integrated.

**References**

[1] Luneburg R, Herzberger M. Mint: A

*Additive Manufacturing for Antenna Applications DOI: http://dx.doi.org/10.5772/intechopen.92363*

> modeling. Journal of Materials Processing Technology. 2009;**209**

[9] Sood A et al. Improved dimensional accuracy of fused deposition modeling processed part using grey Taguchi method. Journal of Material and Design.

[10] Ang K et al. Investigation of the mechanical properties and porosity relationships in fused deposition modeling-fabricated porous structures. Rapid Prototyping Journal. 2006;**12**(2):

[11] Roberson D, Wicker R, MacDonald E. Ohmic curing of printed silver conductive traces. Journal of Electronic Materials.

Fabrication of low dielectric constant composite filaments for use in fused filament 3D printing. Additive Manufacturing, Science Direct. December 2019;**30**. Available from:

[13] Castles F, Isakov D, Lui A, Lei Q, Dancer CEJ, Wang Y, et al. Microwave dielectric characterization of 3D-printed BaTiO3/ABS polymer composites. Scientific Reports. 2016;**6**. Available from: https://doi.org/10.1038/srep22714

[14] Parsons P, Larimore Z, Mitchell G. Composite materials development for fused filament fabrication of RF systems. In: Proceedings of Applied Computational Electromagnetics Symposium (ACES). Monterey, CA;

[15] Dorsey W, Zaghloul A. Dualpolarized dual-band antenna element for ISM bands. In: Proceedings of IEEE

(15-16):5593-5600

2009;**30**(10):4243-4252

2012;**41**(9):2553-2566

[12] Parsons P, Larimore Z, Muhammed F, Mirotznik M.

https://doi.org/10.1016/j. addma.2019.100888

March 2020

100-105

[3] Moulart A, Marrett C, Colton J. Mint:

ceramics by fused deposition of ceramics.

Polymeric composites for use in electronic and microwave devices. Journal of Polymer Engineering and Science. 2004;**44**:588-597. DOI:

[4] Agarwala MK et al. Structural

In: Proceedings of Solid Freeform Fabrication Symposium. Austin, TX.

[5] Duncan B et al. 3D printing of millimeter wave RF devices. In: Workshop on Additive Manufacturing of Antennas and Electromagnetic Structures. McLean, VA: MITRE; 2017

[6] Castles F, et al. "Microwave Dielectric Characterization of 3D-Printed BaTiO3/ABS Polymer

Composities", US National Library of Medicine, PMC4778131; 2016. Available from: https://www.ncbi.nlm.nih.gov/ pmc/articles/PMC4778131/#b20

[7] Rao Y et al. Novel polymer-ceramic nanocomposite based on high dielectric constant epoxy formula for embedded capacitor application. Journal of Applied Polymer Science. 28 Nov 2001;**83**(5): 1084-1090. Available from: https://doi.

org/10.1002/app.10082

**199**

[8] Ahn D et al. Representation of surface roughness in fused deposition

10.1002/pen.20053

1995. pp. 1-8

mathematical theory of optics. American Journal of Physics. 1996;**34**

(80). DOI: 10.1119/1.1972799

[2] Roper GB, Yarlagadda S, Mirotznik M. Fabrication of a flat Luneburg lens using functional additive manufacturing. In: Proceedings of National Radio Science Meeting (Joint AP-S Symposium), USNC-URSI, Memphis, TN; 6–11 July 2014; DOI: 10.1109/USNC-URSI.2014.6955649
