Spin-wave band-pass filters for 6G communication

Spin-wave (SW) filters using single-crystal yttrium iron garnet (YIG) is an attractive technology for integration in frequency-adjustable or frequency-tunable communication systems¹. However, existing SW devices do not have sufficient bandwidth for future 5G and 6G communication systems^2,3, are too large or have strong spurious passbands, creating unintentional cross-channel interference. Here we report a SW ladder filter architecture requiring only a single external magnetic bias, which is enabled by modern micromachining fabrication methods capable of wafer-scale production. The filters developed in this work demonstrate loss as low as 2.54 dB, bandwidths up to 663 MHz, centre-frequency tuning over several octaves from 7.08 to 21.6 GHz and high linearity with an input-referred third-order intercept point of more than 11 dBm in the passband. The operation of the filter is also experimentally demonstrated in a frequency-tunable radio system.