Forensics of a Smartphone

In the hustle and bustle of our daily life, smartphones have been the center of many activities, drastically changing the way we live. Such a small device but has the capability to compress all the conveniences of a mobile phone, a computer, a camera, an alarm clock, a flashlight, and much other uncountable stuff. How can so many technologies be squeezed into a space smaller than your pocket? Follow this article that will lead you through a forensic session of the latest smartphone on the market – the monster of innovations: Samsung Galaxy S20 Ultra.

casing

The first thing to unpack is the casing of the smartphone. Smartphone cases cover the behind of the phone and can be made of different materials, which deliver different advantages and drawbacks accordingly. Metal is a preference in high-end products due to its strong heat conduction, which rapidly cools down high temp devices while delivering an expensive feeling to users. However, metal could also be easily bent which cause the phone to be deformed and good conduction of heat also means that users can fully feel the scorching surface in their hand while playing intensive games.

Another commonly used material besides metal is plastic. Plastic’s elasticity prevents the phone from being deformed upon impacts while being non-metallic induces better signal reception. Although plastic does create a low-priced feeling about the phone, a recent rising trend of casing material is prism-like plastic, which eliminates this drawback. Prism generates a flashy sensation and is able to form colorful effects on the smartphone’s case. Besides, ceramic has also become an option as Huawei uses it for the casing of their P40, delivering a distinctive Oriental fashion.

OVERVIEW

Modern smartphones have an exceptional level of compression, being able to compact hundreds of devices into an extremely confined space. The above detail X-ray and backside image provide us a full view of the Samsung Galaxy S20 Ultra’s internal. A huge space is dedicated to the ultra-large battery with 5000mAh capacity that runs at 3.86V, a tremendous improvement compared to Samsung Note 10+ (4300mAh) and iPhone 11 Pro Max (3969 mAh) [1][2]. On top of the battery is the wireless charging coil that can charge the phone at 15W (100% battery in 1 hour 45 minutes) and reverse charge other devices at 9W.

On the back of the casing panel, between the top camera and the flash is the little microphone (Fig 5.), with 4 circular contact pads that allow it to communicate with the body of the phone. At the bottom is the charging port board & the speaker board being stacked up together beside a square vibrator motor. Fig.6 shows you a small red sticker covering tiny balls inside of the speaker housing. These little guys help the speaker sounds larger than it actually is by making the air move around the balls inside the housing.

CAMERAS

The Samsung Galaxy S20 Ultra has an impressive camera system that makes this phone a true picture-taking beast. The main camera is a 108-megapixel sensor capturing scenes for detailed crop-ins that invariably make you say “wow!”. Its selfie camera also possesses an impressive 40-megapixel sensor. To understand how powerful this camera is, keep in mind that a megapixel is equivalent to 1 million pixels. Common high-quality videos on Youtube enjoy a resolution of 1080p that refers to 2 megapixels. Ultra HD or 4K means there are about 8 megapixels. That monster Samsung includes in its latest S20 is an astounding 108-megapixel camera.

Above the main camera is the Ultra-wide-angle camera which is a 12-megapixel sensor and on the right is the DepthVision camera. Wide-angle cameras use lens whose focal length is substantially smaller than that of a normal lens, allowing users to include more of the scene while not being able to move further behind. A depth camera – or ToF (time-of-flight) camera – provides ranging information, with each pixel is having a corresponding distance value in addition to the usual R, G, and B values. The camera shoots out infrared rays, which then bounce off objects and return to the hardware, helping it to focus correctly on the desired surface. This function enables users to perform a 3D scan for an object and recreate a 3D rendering of it, as well as Quick Measure where realtime measurements of spatial width, height & area can be made.

A year ago in 2019, we’ve witnessed the amazing 50X zoom camera on Huawei P30 Pro, but Samsung has taken the periscope zoom hardware to another level. How do you fit a stack of zoom lenses into a smartphone that’s only 8.8 mm thin? The answer is: turn it sideways. Instead of focusing your image directly onto the sensor, this camera uses a prism to bounce the light sideways at a 90-degree angle just like the submarine periscope. The lens itself is good for a (fixed) 4x magnification—the rest comes from a combination of sensor cropping and binning (48 megapixels pared down to 12) and standard digital zoom, to get to 100X.

MOTHERBOARD

The motherboard is double-stacked, which means there are different flip-chips on both side of the board. Let’s go through one by one:

RAM & SoC: Samsung K3LK4K40BM-BGCN 12GB LPDDR5 RAM layered over Qualcomm Snapdragon 865 SoC (system-on-chip). The Snapdragon is used in North America, China, Korea & Japan, while Exynos 990 is used in Europe & the rest of the world.
Internal storage: Samsung KLUDG4UHDB-B2D1 128GB UFS 3.0 flash storage. MicroSD card can upgrade the storage by 1TB.
Modem: Qualcomm Snapdragon X55 2nd-gen 5G modem.
RFFE: Skyworks SKY58210-11 RF Front-End Module.
RFFE: Qorvo QM78092 Front-End Module.
PMIC: Maxim MAX77705C power management IC.
PA modules: Qualcomm QPM5677 and QPM6585 5G power amplification modules.

Flipping the boards over reveals even more flip chips:

RF Transceiver: Qualcomm SDR865
Wi-Fi & Bluetooth Module: Murata KM9D19075
PMIC: Qualcomm PM8250 power management IC for the Snapdragon SoC
PMIC: Qualcomm PMX55 power management IC for the 5G modem
PMIC: Qualcomm PM8150C power management IC
RFFE: Qualcomm QDM4870 front-end module

Hiding in the edge of the phone are two millimeter-wave antennas, while the third one is situated at the top right over the microSD card location. These antennas are used for 5G mmWave communication, and they are not included in the smaller sibling, the Galaxy S20 which supports sub-6GHz 5G networks only.

SCREEN

Samsung S20 Ultra screen can have a breathtaking refresh rate of up to 120Hz (means the screen can be refreshed 120 times every second), which allows a more responsive feeling when using a pen, playing games, or scrolling more smoothly. A technology name “Adaptive Frequency” will adjust different refresh rates to save power. It can hit 120Hz when high rates are needed for gaming, drop to 60Hz for video playback, 30Hz when you’re messaging, or as low as 10Hz when it’s displaying a still image [3].

The on-board silicon includes the fingerprint module from Qualcomm, the QBT2000 3D Sonic Sensor controller. This device allows fingerprint scanning on the screen’s surface, with a sensor of merely 0.2mm in thickness. It is currently the most advanced fingerprint security solution, using ultrasonic to achieve a 3D rendering of the finger’s surface instead of the previous outdated optical and capacitive solution.

CONCLUSION

Samsung continues to bring new interesting innovations to its phones. While the smartphone world is converging into iterations and safe bets, it is refreshing to see a new trial of different technologies. Some may stick and some may eventually turn out to be of little use, but that is exactly the process of evolution. Hope that this forensic session could bring you a deeper understanding of what is packed inside our powerful black boxes which have tremendously changed human daily lives in the era of Information.

Reference:

1. “Galaxy Note 10 specifications”. Samsung. Retrieved on 2020-08-19.
2. “iPhone 11 / Pro / Max battery capacity: size revealed”. www.phonearena.com. Retrieved on 2020-08-19.
3. Richard Lawler. “Samsung’s 120Hz mobile displays use variable refresh rates to save power”. www.endgadget.com. Retrieved on 2020-09-06.
4. “Samsung Galaxy S20 Ultra Teardown“. ww.ifixit.com.