The protagonist of this test is a short-distance contactless millimeter-wave connector based on ST60, the model is SK202. SK202 needs to be used in pairs, so a set of at least 2 almost identical boards. A simple understanding of a pair of SK202 is a "space network cable", which nominally supports Gigabit Ethernet (that is, the rate reaches 1Gbps).
As shown above, a pair of SK202 is divided into 2 small boards, SK202A and SK202B, which are almost the same except for the antenna.
Taking any one of the boards as an example, there are 4 large components from left to right:
1. RJ45 network port. This is the most common network port, and with the Ethernet chip behind it, it supports Gigabit Ethernet.
2. HR682430E. Network isolation transformer, standard configuration of RJ45 network port.
3. RTL8211FS. The Ethernet PHY chip from Realtek supports 10/100/1000M Ethernet data transmission and reception.
4. SKA2DHV (SK202A) or SKA2DVH (SK202B). 60GHz mmWave transceiver provided as a stamp hole. It includes 2 ST60A2 millimeter-wave chips from STMicroelectronics (one receiving and one transmitting), and two horn antennas are provided for signal sending and receiving.
The board is powered by an independent DC interface, or powered by a Micro USB interface. This is a low-power device, you can just find a qualified charger or get power from the computer's USB port.
Note that the polarization directions of the two pairs of antennas are perpendicular to each other.
The above components 1, 2, and 3 constitute a simple network card, which is a traditional solution, and the focus is on component 4, the millimeter wave module.
The 60GHz millimeter wave looks tall, but the actual module is the smallest. The official nominal size of the ST60A2 millimeter wave chip is only 2.2 mm x 2.2 mm x 0.8 mm.
Although there is no schematic diagram or layout, it is not difficult to see that the peripheral circuit of ST60A2 should be very simple. Except for the antenna, each ST60A2 only needs 4 passive components.
