TDK low-temperature co-fired ceramic package antenna equipment, a key component of 5G multi-antenna

     Services based on the fifth-generation (5G) mobile communication system have begun, featuring "multiple concurrent connections" and "ultra-low latency" in addition to "ultra-fast speed and large capacity" to download movies in just a few seconds. TDK plans to offer low-temperature co-fired ceramic Packaged antenna (LTCC AiP)1 devices, which will be a key component of 5G multiple antennas and play an important role in small cell base stations.

     With the emergence of the IoT/IoE society where everything is connected, the focus is gradually shifting to 5G communications as a key infrastructure element, and the market is predicted to grow rapidly. While the market for 5G-related products is only taking shape, the global market is expected to be worth $38 billion by 2023. Products and services related to small cell sites are expected to account for about 70% of the total value. (Fuji Chimera Research Institute, Inc. "Future Vision of Core Technologies for 5G/ High Speed and High Capacity Communication", 2018)

     The reason for this rapid growth is that 5G communications use millimeter wave 2, so each 5G base station covers only a limited area. As a result, 5G communications network configurations are characterized by a large number of small cell sites that, when initially installed, will cover every macro base station that provides coverage through traditional communications base stations. In addition, because millimeter waves are easily blocked by objects, more small cell towers need to be installed in locations such as train stations, shopping malls and stadiums.

     Multiple antennas that integrate multiple antenna elements play an important role in small cell base stations. The key technology in 5G communications is beamforming 3, which converts radio waves into beams and then transmits the beams to each terminal. For example, in sports events held in stadiums, the technology can transmit athlete movements from all angles to a large number of audience terminals, broadcast multiple games simultaneously in real time, and provide augmented reality audience services. The technology will enable a whole new way of watching events.

     In beamforming, radio waves are converted into beams by controlling the phase of the signal radiated from the antenna elements of multiple antennas. Therefore, array antennas that integrate multiple antenna elements gradually develop into multiple antennas. Since bandpass filters (BPF) and integrated circuits (ics) are also connected to array antennas, these antennas need to be small and thin, and ensure advanced functionality for the entire system.

    TDK has developed an "LTCC AiP device" for 5G small cell base stations that integrates antenna elements and BPF into LTCC multilayer substrates using the unique LTCC technology accumulated over the years. A key feature of the device is the use of a newly developed low dielectric material in the antenna layer, so that high gain can be achieved even in millimeter bands. Other advantages include excellent environmental adaptability and heat dissipation, as well as design and evaluation freedom, and the device provides excellent performance for 5G communication base station multiple antennas.

     LTCC technology is a construction method developed for the production of high frequency components. Ceramic sheets developed for sintering at relatively low temperatures (about 900°C) are pressed in multiple layers to achieve low temperature sintering, and microscopic wiring paths of metal conductors are formed on dielectric ceramic plates, with conductor patterns enabling them to act as inductors or capacitors. Due to the different sheet materials used for the capacitor layer and the inductor layer, advanced co-firing technology is required. For such co-firing of different materials, TDK pioneered an advanced LTCC construction method and has commercialized high-frequency filters and front-end modules for mobile communication terminals.