Design of Millimeter-Wave Antenna-in-Package(AiP)for 5G NR

For 5G new radio(NR),there are two frequency bands:Frequency Range 1(FR‐1)(low frequency)and Frequency Range 2(FR‐2)(millimeter‐wave frequency).Millimeter‐wave has been officially utilized in mobile applications.The wide bandwidth is the key for the millimeter-wave band.However,higher loss has become the major challenge for the wide use of this frequency range.Antenna array and beamforming technologies have been introduced to resolve the path loss and coverage problems.The key design considerations of the beamforming antenna array are low loss,compact system and small size.Antenna-in-package(AiP)has become the most attractive technology for millimeter-wave front-end system.For the design of AiP,many parameters such as RF transition,material and heat need to be considered and designed properly.The Over‐the‐Air(OTA)testing technology is also very critical for AiP mass production.In this paper,the detail of AiP design and new OTA testing technology are discussed and demonstrated.

Low-fired Y-type hexagonal ferrite for hyper frequency applications

Y-type hexagonal ferrite with planar magnetocrystalline anisotropy has ultrahigh cut-off frequency up to GHz and excellent magnetic properties in hyper frequency range,so that is regarded as the most suitable material in correpongding inductive devices and components.The technology of low temperature cofired ceramics for surface-mounted multilayer chip components needs ferrite to be sintered well under 900℃to avoid the melting and diffusion of Ag inner electrode during the cofiring process.To lower the sintering temperature of Y-type hexagonal ferrite,there are several methods,(1)using nano-sized starting powders,(2)substitution by low-melting elements,(3)adding sintering additives,and(4)introducing lattice defect.In this paper,the effects of different methods on the sintering behavior and the magnetic properties were discussed in detail.