How Converters Can Make RFID Labels

Challenges

UHF is not entirely a bed of roses even though its use may overtake HF (the most popular frequency) in several years to come. Although conventional far-field UHF gives unusually long range without recourse to a battery in the tag—several meters—the range is unpredictable because of sensitivity to water and metal, even if it is not between the tag and the interrogator. There are workarounds for this and they usually take the form of a wide variety of very different antenna patterns that are screen-, flexo-, or gravure-printed for the particular application. For example, the electronic product code (EPC) chip supplier Impinj offers its “banjo” and “propeller” designs on license to those using its chips and also combines near-field/far-field antenna designs. Others offer asterix, zigzag, paddle, strip, and other weird and wonderful shapes of antenna, all easily printed with conductive ink.