5G by phone baseband is not enough! Antenna design also have to be operated

5G mobile phone is about to come out, but careful not difficult to find children’s shoes, 5G phone overall more expensive, bigger battery, but will also bid farewell to the full integration of all-metal design. Behind these changes, the hidden little secret and antennas.

5G phone from changes


Samsung Galaxy S10 and millet and other mobile phones exist MIX3 version 4G and 5G version, which not only greatly enhance the price, Galaxy S10 version 5G (4500mAh) battery capacity Galaxy S10 + 4G version (4100mAh) and more than 400mAh, while millet MIX3 Version 5G (3800mAh) battery also increases 500mAh than 4G version (3300mAh), it is to increase the battery power to cope with greater 5G.

In addition, the choice 5G phone body material is also completely abandon all-metal design integrated, comprehensive use of glass or plastic cover, thereby ensuring the strength of the received signal 5G, provide a solid physical downlink rate exceeding 2Gbps Base. So, 5G phone why higher price and power consumption? The requirements of overflow signal more demanding?

RF to the antenna core

3G and 4G era, Modem (modem, known as base band) is a core element determines phone network performance.

5G to the era of radio frequency (circuit) and antenna (design) will become the core further juxtaposed with Modem, and more test mobile phone manufacturers R & D capabilities.

The so-called “RF circuits” that receive path inside the phone, and collectively transmit path circuit assembly of the present vibration, may also be extended down a subdivided RF transceiver chip, a radio frequency transceiver power management chip, an antenna, an antenna switch, a filter , high discharge pipe, an intermediate frequency blocks, the frequency synthesis blocks, receiving the voltage controlled oscillator, and many other modules.


Which, in turn antenna design has become a priority, it will affect the mobile phone number and the highest frequency up / downlink rate can be achieved can support.

It should be noted that the operation of the antenna is obtained by conversion of the electric and magnetic fields, and receiving electromagnetic radiation to complete energy. In addition to 2G, 3G, 5G and even beyond 4G mobile communication signal, Wi-Fi, Bluetooth, GPS, NFC and wireless charging (coil) antenna and the like also need to function as a carrier for receiving and transmitting signals.


As mobile phones become thinner, increasing the proportion of the screen, like in a limited space for these uses different antennas harmony is not easy. Therefore, before understanding the new requirements of the proposed antenna 5G, you may wish to review the changes in the smart phone antenna in these years.


Before the 5G antenna design

Remember the first cell phone antennas look like it?

Yes, it is long on the phone, “head” as if today router antennas are generally exposed to influence today’s perspective is very unsightly.


In 1999, Nokia 3210 and finally “get rid of” the unexpected presence of a built-in antenna design was first introduced in mobile phones, and has continued ever since.

But, from a functional machine to today’s latest smart phone, its built-in antenna material, location and technology are a qualitative change.

Flexible antenna on the FPC parameter

Age features built-in antenna we not say to iPhone 1 as the representative of the early smart phones were powered by a built-in antenna technology called “FPC” (Flexible PrintedCircuits, flexible circuit board), which is a high reliability, thin, good folding printed circuit board.


And the conventional antenna by the metal dome + plastic composition as compared to the stent, includes a FPC easily modified low mold development cost advantages, as long as the FPC assembly attached to the surface of a material, until now there are many phone NFC antenna still using FPC technology.

I.e., an intermediate plastic film interposed FPC film made of a copper wire


Attempts from the metal frame

In order to enhance the quality of early smart phones, cheap plastic texture certainly does not meet the requirements. In the era of iPhone 4, Apple began introducing stainless steel metal frame, with front and rear glass panel called the phone in the same period, “Yan value play.” Comparative wonderful 4 iPhone antenna design, which complex shape welded metal sheet in a metal frame, so that the antenna is acting as a border.

The question is, the signal has a strong metal material shielding effect, iPhone4 permeable in order to allow the various metal frame signals, but also specifically in the open frame 2 slot (two-stage embodiment) for a signal overflow.

However, this design is still serious Bug– when gripping the lower part of the phone, the connection may cause a short circuit at the two-stage antenna, resulting in signal quality seriously diminished, this problem is called “death grip” in the year .

To solve this Bug, Apple has recommended be averse iPhone 4 users to use protective cover, metal frame and then to the iPhone 4S adds a gap, also with three-stage program and receive diversity is no longer a death grip problems.


So far, mobile phone manufacturers have recognized the contradictory relationship between the metal material and signal, all metal frame of the phone will set aside a few gaps on the border; will choose the three-body design with metal back cover, that is, the middle is a metal, a plastic upper and lower ends; when integrated all-metal body, will also leave the nano article design signal of the injection molding process, to reduce the effect of the reception signal to the handheld antenna.

LDS antenna become the trend


Smartphone keen introduction of a metal material, and increasingly thin phone body occasion, an FPC process antenna performance and reliability requirements are difficult to meet, at this time another LDS (Laser DirectStructuring, laser direct structuring) of the built-in antenna process on the surface.


LDS may utilize computer-controlled movement of the laser according to the pattern of conductive tracks, the laser projector will shine on the three-dimensional plastic injection molding device, whereby plated metal layer having a thickness of 5 to 10 micrometers, and ultimately the three-dimensional circuit material.

Briefly, the LDS is a kind of plastic material may be of metal plating and antenna pattern forming technique, it is higher than the accuracy of the FPC, better stability, directly in the metal (or glass) cover inner layer plastic coated stents various antenna patterns, thus saving the internal space of the phone, and to prevent mutual interference inside the device.

Full screen headroom dilemma

When entering full-screen smartphone era, many new products began to pursue “screen share” this parameter, thus the full-screen mobile phones have launched a “forehead” and “chin” border “war of annihilation.” The question is, various smart phone antenna is located just near the top and bottom border, in order to avoid mutual interference between the antenna and other components, we need to leave enough “antenna clearance region.”


In the traditional 16: 9 screen era, leaving the antenna clearance region more in between 7mm to 10mm, and to the full-screen era, clearance area on the left of 3mm to 5mm.

According to traditional thinking, this space is difficult to solve the interference between the antenna and other components, as well as play performance potential 4G network (need 500 mm2 area of ​​the antenna).

In this case, the process needs to LDS antenna and coordinated operations of the other techniques and materials.

For example, the introduction of this low LCP loss coaxial cable instead of a flexible material, the adapter circuit board, the RF power to enhance the open-source unit, etc., using more better electrically tunable devices, but more effective solution, LDS is the use of the antenna and other components into one, such as a plastic liner covering the surface of the PCB, the speaker unit can be used to plate the surface of the antenna pattern.

5G antenna design era

Early in Kirin Snapdragon 835/845 and 970 times, many high-end mobile phone by 4CA (carrier aggregation) technique and 4×4 MIMO (Multiple Input Multiple Output antenna array) technology to obtain the downlink rate over 1Gbps, which entered the 4.5G network threshold. 5G to the Internet age, the minimum requirements for downstream rates of 2Gbps also play a (theoretical up to 20Gbps), but also need to have lower latency and support for all things Internet.

The question is, to achieve the above-described specific properties 5G networks, require radio waves of millimeter wavelength “millimeter wave”, while the 4G network uses a millimeter wave “centimeter wave” signal attenuation compared very powerful, it can not be free in increasing the transmit power (no security) under the premise that only minimize shield the signal on the phone body material, and further increase the number of transmit antennas and receive antennas.

In this environment, the traditional all-metal body design integrated nature have to completely exit the stage of history, and glass and ceramic-based materials will become the meat and potatoes of the eyes of the new phones.

5G phone’s price Why is more expensive? Embodied behind this, it is the new antenna arrays of cost and difficulty of design. For example, high-pass ready for the snapdragon 855 mobile platform and snapdragon X55 modem model for the QTM052 the mmWave Millimeter module, it sets 5G radio transceiver, a power management IC, RF front end and the phased array antenna to a achieve a once unimaginable compact design.

Qualcomm said, in order to improve the ability of the device to signal attenuation and interference, and can install up to four QTM052 5G modules on a cell phone, behind the final cost should be passed on to consumers.

Further, as the first batch into the era of 4.5G Samsung Galaxy S8 (2017 released in), which is an internal antenna for mobile communication reached 5, comprising two main antenna and the diversity antenna 2 a carrier aggregation an antenna, wherein the primary antenna and the diversity antenna may be composed of just receiving antenna in 4X4MIMO mode.

5G at times, want to achieve a higher downstream rate 4X4MIMO only the minimum threshold, 8X8MIMO is the mainstream, conservative at this time but also in the number of antennas 8-10, the sixth generation of Wi-Fi technology also requires MIMO antenna array with, this trend is the layout of the phone’s internal antenna put forward higher requirements.


5G mobile phone antenna design schematic

More and more complex antenna array antenna, will naturally bring to enhance the power, and this is why 5G phone common reasons will further increase battery capacity.


In the era of 4G mobile phone, the same specifications of smartphones on network performance (downstream rates) basically at the same level. And might arise between 5G mobile phone antenna design due to the large difference, known 5G phone downlink rate of 2Gbps there is a minimum and maximum 4.6Gbps, these are the need to attract our attention indicators.

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