Issue link: https://iconnect007.uberflip.com/i/1460418
MARCH 2022 I PCB007 MAGAZINE 37 per vendors have responded to the industry's needs and greatly improved surface rough- ness to minimize skin effect and improve peel strengths to promote optimal adhesion of the dielectric material to the treated foil. Figure 2 shows the recent improvement in copper sur- face topography. Description of PCB Prototypes ITEQ Corporation and INAOE collaborated to design two test vehicles to investigate the sensitivity of patch antenna structures to Dk and Df variability over spatial material inhomo- geneity and across millimeter wave frequen- cies. e four-layer hybrid material stackup shown in Table 1 was designed with ITEQ's IT-88GMW high performance RF material; 5 mil cores, constructed with 1/2 oz ultra-low roughness copper. is critical layer was supported with a non- functional 50-mil standard IT-180 high Tg material core and prepreg, to improve rigid- ity and minimize measurement-induced errors due to warpage or flexure of the thinner radio frequency-grade performance dielectric core. e stackup details, microstrip impedance tar- get, surface finish and layer dimensions are shown in Figure 3. Table 1: Attributes of the RF material chosen for antenna. Figure 3: Stackup construction for the prototype. Figure 4: PCB serialized layout for test vehicle fabrication.