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The paper presents design of 60GHz parallel coupled-line filters with Chebyshev passbands. Etching limit of printed circuit board technology has been taken into account and analyzed. Three filters, the center operation frequency are all 60GHz, are designed with pre-distortion based on the law of fabrication tolerances, including two conventional parallel coupled-line filters and a V-shaped one which has the advantage of input and output at the same horizontal. The comparison, between measured results with the simulation and post-simulation results based on physical dimensions of fabricated filters covered actual etched size, is presented. It is verified that the V-shaped parallel coupled-line filter after considering fabrication tolerance has a good performance and could apply to millimeter wave system.

The paper presents the implementation of three 60 GHz patch antennas, including a single patch antenna, two antenna arrays with 4×1 and 4×4 patch unit respectively. The antennas are designed for front-ends of 60 GHz wireless communication subsystems. To acquire a more concentrated radiation direction and a higher gain, two antenna arrays are designed which increase the propagation distance of the communication subsystem. A four-way power divider combined with a series and parallel network is employed to feed for the antenna array which improves the bandwidth performance of antenna arrays. These antennas are fabricated based on Rogers RT/duroid 5880 substrate. The measured results fit well with the simulated data. This is a very difficult work in such a high frequency band and rarely seen in other papers. The 4 × 1 antenna array was successfully applied in a transceiver system. The bandwidth of the single patch antenna is 3 GHz and both of the arrays are around 10 GHz with the return loss better than −10 dB. The maximum gains are 7.65, 12.5, 18 dBi, respectively.

The graphene coplanar waveguide (CPW) has recently been found to have large insertion loss (typically larger than 50 dB/100 μm), which mainly results from the large resistance of graphene. The poor radio-frequency transmission property of graphene hampers its application in interconnect, a low loss material is thus required. In this paper, low-resistance graphite CPWs with effective graphite length up to 200 μm were fabricated. A record low insertion loss of graphite CPW (2.76 dB/100 μm) is demonstrated, and the average insertion loss of our graphite CPWs is only ∼1/5 of that of our monolayer graphene CPWs. Moreover, we find the insertion loss of graphite CPW may be even smaller at higher frequencies. Our investigation shows that graphite is a possible candidate for interconnect and may even be more applicable at ultra-high frequencies.