Star Semiconductor releases high performance TF-SAW Band 25+66 quadruplex, n41 EN-DC TRx filter, Band 20+28 filter

judy December 21, 2023

On December 20, 2023, Zhejiang Xingyao officially released high-performance Band 25+66 quadriplex, n41 TRx, and Band 20+28 Dual-Rx filter chips based on TF-SAW process, using Xingyao's new generation of enhanced TF-SAW technology. The product performance and stability have reached a new level, and the overall performance of the three products has reached the international first-class level, showing the comprehensive product layout of Xingyao Semiconductor in TF-SAW independent process. Xingdian Semiconductor adheres to the line of independent research and development of high-end products, continuously enhances the technical level of the core field, and has a continuous leading level in the research and development of TF-SAW high-performance filters and its industrialization technology. At present, it can provide a comprehensive, stable and large number of complete sets of filter products with world-class performance. Includes all kinds of chips such as quadruplex, diplexer, TRx filter, Dual-Rx filter and so on.

Part 1. New generation TF-SAW high-performance Band 25+66 quadruplex

This time, Xingdian Semiconductor officially launched the Band 25+66 quadruplex based on the new generation TF-SAW process, and the original version is fully iterated and upgraded. The introduction of this quadruplex will bring new technological breakthroughs and innovations to the field of wireless communication. This is not only a technical innovation, but also an important part of improving the user experience. Its high performance and reliability will provide customers with a better user experience and higher performance levels. Two general package sizes have been released at the same time: standardized size 2.5mm x 2.0mm and miniaturized size 2.0mm x 1.6mm, which will also provide a better solution for the application needs of various wireless communication systems.

Fig.1. Actual photo of Band 25+66 Quadruplex product of Sidian semiconductor (top: 2520 size, bottom: 2016 size)

The Band 25+66 quadruplex chip released this time adopts a new generation of enhanced TF-SAW technology independently developed by Sidian Semiconductor. Relying on its own strong R & D and design team, the Band 25+66 quadruplex has achieved a breakthrough in miniaturization, and achieved the device performance goals of low insertion loss, high isolation, high out-of-band suppression, and high power tolerance. It is compatible with the requirements of a variety of commonly used downlink carrier aggregation. Band 25 Tx plug loss is less than 2.0dBint, Rx plug loss is less than 2.4dBint, Band 66 Tx plug loss is less than 1.7dBint, Rx plug loss is less than 1.7dBint, Band 25 and Band 66 respectively transmit/receive isolation exceeds 55dBint. Band 25 and Band 66 also have a cross isolation of more than 55dBint. All the indicators can reach the international first-class design level, and the device size has reached the leading level of 2.0mm x 1.6mm, the smallest size in the world. At the same time, the excellent temperature drift coefficient (~-10ppm/℃) makes the device's performance at high and low temperatures very stable, more suitable for the complex use environment of large customers.

Fig.2. Test performance of star Obsidian semiconductor TF-SAW Band25+66 quadruplex

（a）Band 25 Tx Insertion Loss；（b）Band 25 Rx Insertion Loss；(c) Band 66 Tx Insertion Loss; (d) Band 66 Rx Insertion Loss; (e) Band 25 Tx Attenuation, wideband; (f) Band 25 Rx Attenuation, wideband; (g) Band 66 Tx Attenuation, wideband; (h) Band 66 Rx Attenuation, wideband; (i) Band 25 TRx Isolation; (i) Band 66 TRx Isolation; (k) Band 25 Tx to Band 66 Rx Isolation; (l) Band 66 Tx to Band 25 Rx Isolation

Part 2. New generation TF-SAW high-performance n41 EN-DC TRx filter

The n41 filter chip released by Star Obsidian Semiconductor continues the advantages of small size and high out-of-band suppression of the previous generation. The package size is 1.1mm x 0.9mm and the operating frequency is 2496 ~ 2690MHz. The product adopts TF-SAW technology route and EDA development software platform developed by Xingdian Company and many unique patented technologies. The new generation of chip products released this time can reach PC2 power level, support HPUE, support 5G mobile phone NSA application, and the anti-static ability and moisture resistance level also reach the international first-class.

Fig.3. Real shot of Star Obsidian semiconductor TF-SAW n41 TRx filter

The published n41 TRx filter has excellent band selectivity, with excellent performance of interpolation loss and out-of-band suppression. The typical insertion loss of the all-band passband can reach 2.2dB, and the typical insertion loss of the Band 41(2515 ~ 2675MHz) in China can reach 1.5dB. The suppression of the near-end Wi-Fi high channel is greater than 20dBint, and the suppression of the band 1710~2170MHz is greater than 32dB. It supports the EN-DC function of Band 3, Band 25, and n41.

Fig.4. Test performance of star Obsidian semiconductor TF-SAW n41 filter

(a) TRx Passband; (b) VSWR; (b) TRx Narrowband Attenuation; (c) TRx Wideband Attenuation

Part 3. TF-SAW High performance Band 20+28F Dual-Rx filter

The Band 20+28F Dual-Rx filter chip released this time, with a package size of 1.4mm x 1.1mm, adopts a new generation of enhanced TF-SAW technology independently developed by Xingdian Semiconductor, which can be applied to the Band 20 receiving operating frequency (791 ~ 821MHz). Band 28F receiving operating frequency (758 ~ 803MHz).

Fig.5. Real shot of Star Obsidian TF-SAW Band 20+28F Dual-Rx filter

TF-SAW filters with high Q value can meet the high requirements of out-of-band steep drop. At the same time, the high Q value also brings better passive performance, and the Band interpolation loss and out-of-band suppression performance are excellent, the typical Band 20 Rx passband loss is less than 1.9dB, the typical Band 28F Rx passband loss is less than 1.7dB, and the Band 20 Tx band suppression is more than 41dB. The suppression of Band 28F Tx band is greater than 42dB, and the comprehensive performance has reached the international first-class level, surpassing the performance of the same product of the top filter or RF company in the United States and Japan.

Fig.6. Test performance of star Obsidian TF-SAW Band 20+28F Dual-Rx filter

(a) Insertion Loss; (b) VSWR; (c) Narrowband Attenuation;  (d) Wideband Attenuation

As a "killer" product, such high-level RF devices as TF-SAW filters, after 3 years of intensive product development, Xingdian Company has independently developed and completed TF-SAW full-band filters, a series of key frequency band diplexers and filters have completed mass production of high-quality delivery, and the overall shipment of TF-SAW products has reached the highest in China. For TF-SAW characteristic process, Xingyao has signed a long-term supply agreement with substrate manufacturers and reached in-depth cooperation, customized development of various substrate materials, product application coverage range from 600MHz to 2.7GHz, can fully adapt to the full range of communication frequency band requirements. In the future, more TF-SAW filter products with different frequency bands and different application scenarios will continue to be launched. The many products released this time are not only technical innovation, but also a response to customer needs, which reflects the technical reserve and innovation ability of Xingyao semiconductor in the field of RF front-end filtering. At the same time, Xingyao Semiconductor will continue to focus on technological innovation and upgrading, provide customers with better services and more advanced products, and jointly promote the progress and development of wireless communication technology with upstream and downstream partners in the industry.

Fig.7. List of Star Obsidian semiconductor TF-SAW mass production products