# Design of a Wideband Antenna for Wireless Network-On-Chip in Multimedia Applications
## 4 Comparison of the Designed Antenna vs. the State-of-the-Art
Similarly, the slot bow-tie antenna in [62] has an area 2.5 times larger than the proposed design; realized in 180 nm SiGe technology, and using a PEC layer under the substrate, [66] achieves a gain from \(-3\) dBi to 0 dBi operating from 70 GHz to 110 GHz. However, for this antenna, the radiation pattern is directed along the Z-axis, which is unsuitable for WiNoC applications where the communication is towards co-planar nodes. High gain antennas have been proposed at 60 GHz such as the Fan-like antenna in [67]. The antenna in [67] exhibits a beamwidth of 184 degrees, a gain varying from 1.6 dBi to 6.4 dBi from 57 GHz to 64 GHz, but for an area of 156 mm\({}^{2}\), which is orders of magnitude higher than our proposed design. Some antennas operating at around 60 GHz are reviewed in [93; 94], but their area occupation is at least tens of mm\({}^{2}\). Therefore, they are more suited for wireless sensor networking applications, in off-chip short-range communications, rather than for WiNoC. As far as the antennas at sub-GHz are concerned, as in Ref. [68; 70; 71; 81], the gain of the antennas is higher than the gain of the proposed bow-tie antenna, but the bandwidth in [68; 70; 71; 81] is so low that the data-rate is limited to a few kb/s. Such antennas are suitable for wireless sensor networks, but not for on-chip high-rate connections among several processors or between a processor and a memory tile. Carbon Nanotube (CN) antennas have also been proposed in literature in Ref. [75; 76; 77] to achieve a Terahertz frequency operating range. The CN antennas, operating in Terahertz frequency range, can provide much higher communication data rates than on-chip antennas, operating up to 100 GHz. The CN antennas can also have extremely high current density, compared with copper, thus allowing for a higher transmission power. Therefore, they can be suitable for long-distance communications. However, CN antennas are still facing significant manufacturing challenges. The design of Ultra Wide Band (UWB) antennas was also proposed for on-chip wireless communication in Ref. [78; 79; 80]. The UWB antenna design approach can provide high bandwidth, low power and short-range communication for WiNoCs. However, the UWB-based antenna in Ref. [78; 79; 80], implemented in a 180 nm CMOS technology as a meander-type dipole antenna with a length of about 3 mm, and integrated in a complete on-chip transceiver, allows for a transmission range limited to 1 mm. The area occupation of the antenna in the layout of Ref. [79], including the feeding circuitry, is about 2 mm\({}^{2}\), i.e., 4 mm \(\times\) 0.5 mm. The short transmission range, compared with the current die area, would require multi-hop wireless communication across the chip, which makes it less efficient for a communication distance above 1 mm. Another class of antennas proposed for WiNoC is the PLPA (planar log-periodic on-chip antenna) one, see Ref. [82; 83; 84]. The authors of [82; 83; 84] propose the design of an on-chip PLPA with a bandwidth of about 10% of the central frequency, e.g., 6 GHz of bandwidth around a central frequency of 60 GHz and featuring end-fire directivity. It is to be noted that the PLPA in [82; 83; 84] can also resonate at other frequencies, e.g., 44 GHz. From CAD simulations, the HPBW of the PLPA is \(33^{\circ}\) along the end-fire direction, whereas the HPBW along the elevation is \(30^{\circ}\). At 60 GHz, the antenna gain is \(-38.65\) dBi. The longest dimension of the antenna is 1.1825 mm, which is comparable to the wavelength of the signal in the dielectric medium. The area is about 1.4 mm\({}^{2}\), but this value does not include the feeding network, which instead is included in the area values of the other antennas considered in Table 2. It is worth noting that the performance of the PLPA in [82; 83; 84] at 60 GHz, in terms of bandwidth, gain and HPBW, is lower than the design proposed in this work. Several on-chip antennas are proposed by [PERSON] et al. in [85; 86; 87; 88; 89; 90; 91; 92].