Abstract: A radio frequency transceiver having a printed circuit board (PCB) on which are located a plurality of components, the PCB being sandwiched between a base and a cover. The cover having a plurality of components for accommodating each of the plurality of components to separate the plurality of components into a number of virtual modules. All interconnects between the number of virtual modules are in the PCB. The PCB has a radio frequency (RF) layer, a RF ground layer, a direct current (DC) layer, and a DC ground layer. There is a plurality of via holes from the RF ground layer to the DC ground layer to provide virtual RF ground.

Abstract: A method of recording close contacts for disease control, the method including the steps of using a device to transmit identity and date/time of contact details to a similar device for each close contact. Identity details of the similar device are received and store for at least predetermined time for each close contact. At the expiry of the predetermined time the received identity details may be overwritten if the memory is full. The stored identity details are used to determine identities of persons with whom close contact had been made within the predetermined time. The device has embedded therein a semiconductor processor device, a memory device, a clock and a transmitter/receiver with an antenna.