A planar antenna board comprising: an antenna substrate layer (122, 206) having a first planar surface and a second planar surface opposite the first planar surface; a top conductive layer located on the first planar surface; a bottom conductive layer (124, 207) located on the second planar surface; a first E-band antenna (102, 104) fabricated in the top conductive layer, the first E-band antenna (102, 104) configured to receive/transmit an E-band frequency radio frequency, RF, signal; a second E-band antenna (102, 104) fabricated in the top conductive layer, the second E-band antenna (102, 104) configured to receive/transmit an E-band frequency RF signal, wherein the second E-band antenna (102, 104) is offset in a plane of the first planar surface from the first E-band antenna (102, 104); a periodic array of two-dimensional electromagnetic band-gap, EBG, structures fabricated in the top conductive layer, the periodic array of two-dimensional EBG structures located between the first E-band antenna (102, 104) and the second E-band antenna (102, 104), wherein each EBG structure includes a plurality of slots formed in the top conductive layer, wherein the periodic array of two-dimensional EBG structures is configured to block surface waves in the E-band frequency range, wherein each EBG includes square first conductive regions (202a, 202b, 202c, 202d) located on the first planar surface of the antenna substrate and separated from adjacent first conductive regions (202a, 202b, 202c, 202d) by a first distance (L6, L9), wherein each EBG further includes 'L'-shaped second conductive regions (204a, 204b, 204c, 204d) located on the first planar surface, wherein the second conductive regions (204a, 204b, 204c, 204d) at least partially surround the first conductive regions (202a, 202b, 202c, 202d), wherein the second conductive regions (204a, 204b, 204c, 204d) are separated from the first conductive regions (202a, 202b, 202c, 202d) by a second distance (L7, L8), wherein the first distance (L6, L9) is approximately equal to the second distance (L7, L8), wherein the second conductive regions (204a, 204b, 204c, 204d) are separated from adjacent second conductive regions (204a, 204b, 204c, 204d) by a third distance (L3, L4), and wherein the third distance (L3, L4) is equal to the first distance (L6, L9) and the second distance (L7, L8). an antenna substrate layer (122, 206) having a first planar surface and a second planar surface opposite the first planar surface; a top conductive layer located on the first planar surface; a bottom conductive layer (124, 207) located on the second planar surface; a first E-band antenna (102, 104) fabricated in the top conductive layer, the first E-band antenna (102, 104) configured to receive/transmit an E-band frequency radio frequency, RF, signal; a second E-band antenna (102, 104) fabricated in the top conductive layer, the second E-band antenna (102, 104) configured to receive/transmit an E-band frequency RF signal, wherein the second E-band antenna (102, 104) is offset in a plane of the first planar surface from the first E-band antenna (102, 104); a periodic array of two-dimensional electromagnetic band-gap, EBG, structures fabricated in the top conductive layer, the periodic array of two-dimensional EBG structures located between the first E-band antenna (102, 104) and the second E-band antenna (102, 104), wherein each EBG structure includes a plurality of slots formed in the top conductive layer, wherein the periodic array of two-dimensional EBG structures is configured to block surface waves in the E-band frequency range, wherein each EBG includes square first conductive regions (202a, 202b, 202c, 202d) located on the first planar surface of the antenna substrate and separated from adjacent first conductive regions (202a, 202b, 202c, 202d) by a first distance (L6, L9), wherein each EBG further includes 'L'-shaped second conductive regions (204a, 204b, 204c, 204d) located on the first planar surface, wherein the second conductive regions (204a, 204b, 204c, 204d) at least partially surround the first conductive regions (202a, 202b, 202c, 202d), wherein the second conductive regions (204a, 204b, 204c, 204d) are separated from the first conductive regions (202a, 202b, 202c, 202d) by a second distance (L7, L8), wherein the first distance (L6, L9) is approximately equal to the second distance (L7, L8), wherein the second conductive regions (204a, 204b, 204c, 204d) are separated from adjacent second conductive regions (204a, 204b, 204c, 204d) by a third distance (L3, L4), and wherein the third distance (L3, L4) is equal to the first distance (L6, L9) and the second distance (L7, L8).