60GHz

高门槛啊。有能力作器件才行。

in reference to:

"The challenges
A world of possibilities, but also a world of technological challenges arises with the 60GHz band. First of all, such a huge carrier frequency—an order of magnitude higher than current standards—imposes a lot of hazards to the analog and antenna designers.

Moreover, when you aim at developing single-chip 60GHz radios, using silicon CMOS technology, the technological challenge is even greater. The 45nm technology node for CMOS is required to realize these radios but only research centers have ready access to these advanced technology nodes can get insight into the analog characteristics of the 45nm transistors.

A second challenge is the huge bandwidth of 7GHz at which the 60GHz radios have to work (from 57 to 64GHz). This means the operating frequencies can vary about 15% as compared to only 3% for Wi-Fi (from 2.4 to 2.485). This is especially hard for the front-end, synthesizer and antenna design.

Thirdly, the analog-to-digital converters and digital-to-analog converters have to operate at a high sample rate of about 4Gsamples/sec at a resolution of 5 to 6 bit. Such characteristics are difficult to realize in CMOS, especially with reasonable power consumption. This high sample rate is also challenging for the digital processing unit of the radio. Several good ultra-low-power ADCs were presented at ISSCC2008.

A fourth problem with 60GHz radios is the low signal to noise ratio (SNR). The reason for this is twofold: the high carrier frequency implies a low receive power; and, a high bandwidth (2GHz for 60GHz communication) contributes to a high noise level at the receiver side; hence, the system works at low SNR.

To circumvent this phenomenon, beam-forming techniques both at the receiver and transmitter sides are applied for 60GHz communications. Intelligent beam forming is achieved by using multiple antenna paths combined with programmable phase shifters.

For very demanding applications in terms of data rate, larger antenna arrays are needed. Another consideration is that beam forming is more important for plugged applications (e.g. wireless HDMI) than for nomadic applications (video kiosk) since in the latter case, part of the problem can be solved by bringing the portable device closer to the video kiosk.

And finally, the fifth challenge with 60GHz communications is that designers have to be aware of the fact that the standard will incorporate three physical (PHY) layers: one single-carrier modulation with frequency domain equalization (SC-FDE) and two OFDM variants."
- 60GHz: Achieving the ultimate wireless dream | Wireless Net DesignLine (view on Google Sidewiki)