  Ubiquitous multicore processors nowadays rely on an integrated
packet-switched network for cores to exchange and share data. The performance
of these intra-chip networks is a key determinant of the processor speed and,
at high core counts, becomes an important bottleneck due to scalability issues.
To address this, several works propose the use of mm-wave wireless
interconnects for intra-chip communication and demonstrate that, thanks to
their low-latency broadcast and system-level flexibility, this new paradigm
could break the scalability barriers of current multicore architectures.
However, these same works assume 10+ Gb/s speeds and efficiencies close to 1
pJ/bit without a proper understanding on the wireless intra-chip channel. This
paper first demonstrates that such assumptions do not hold in the context of
commercial chips by evaluating losses and dispersion in them. Then, we leverage
the system's monolithic nature to engineer the channel, this is, to optimize
its frequency response by carefully choosing the chip package dimensions.
Finally, we exploit the static nature of the channel to adapt to it, pushing
efficiency-speed limits with simple tweaks at the physical layer. Our methods
reduce the path loss and delay spread of a simulated commercial chip by 47 dB
and 7.3x, respectively, enabling intra-chip wireless communications over 10
Gb/s and only 3.1 dB away from the dispersion-free case.
