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RF CMOS

RF CMOS is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand RF CMOS rather than just read about it. In short: RF CMOS is a metal–oxide–semiconductor (MOS) integrated circuit (IC) technology that integrates radio-frequency (RF), analog and digital electronics on a mixed-signal CMOS (complementary MOS) RF circuit chip. It is widely used in modern wireless telecommunications, such as cellular networks, Bluetooth, Wi-Fi, GPS receivers, broadcasting, vehicular communication systems, and the radio transceivers in all modern mobil…

RF CMOS — main illustration
RF CMOS — illustration

Key takeaways

  • RF CMOS belongs to engineering; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect RF CMOS to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of RF CMOS from memory before moving on to harder problems.

Reference excerpt

RF CMOS is a metal–oxide–semiconductor (MOS) integrated circuit (IC) technology that integrates radio-frequency (RF), analog and digital electronics on a mixed-signal CMOS (complementary MOS) RF circuit chip. It is widely used in modern wireless telecommunications, such as cellular networks, Bluetooth, Wi-Fi, GPS receivers, broadcasting, vehicular communication systems, and the radio transceivers in all modern mobile phones and wireless networking devices. RF CMOS technology was pioneered by Pakistani engineer Asad Ali Abidi at UCLA during the late 1980s to early 1990s, and helped bring about the wireless revolution with the introduction of digital signal processing in wireless communications. The development and design of RF CMOS devices was enabled by van der Ziel's FET RF noise model, which was published in the early 1960s and remained largely forgotten until the 1990s.

History

Pakistani engineer Asad Ali Abidi, while working at Bell Labs and then UCLA during the 1980s–1990s, pioneered radio research in metal–oxide–semiconductor (MOS) technology and made seminal contributions to radio architecture based on complementary MOS (CMOS) switched-capacitor (SC) technology. In the early 1980s, while working at Bell, he worked on the development of sub-micron MOSFET (MOS field-effect transistor) VLSI (very large-scale integration) technology, and demonstrated the potential of sub-micron NMOS integrated circuit (IC) technology in high-speed communication circuits. Abidi's work was initially met with skepticism from proponents of GaAs and bipolar junction transistors, the dominant technologies for high-speed communication circuits at the time. In 1985 he joined the University of California, Los Angeles (UCLA), where he pioneered RF CMOS technology during the late 1980s to early 1990s. His work changed the way in which RF circuits would be designed, away from discrete bipolar transistors and towards CMOS integrated circuits. Abidi was researching analog CMOS circuits for signal processing and communications at UCLA during the late 1980s to early 1990s. Abidi, along with UCLA colleagues J. Chang and Michael Gaitan, demonstrated the first RF CMOS amplifier in 1993. In 1995, Abidi used CMOS switched-capacitor technology to demonstrate the first direct-conversion transceivers for digital communications. In the late 1990s, RF CMOS technology was widely adopted in wireless networking, as mobile phones began entering widespread use. This changed the way in which RF circuits were designed, leading to the replacement of discrete bipolar transistors with CMOS integrated circuits in radio transceivers. There was a rapid growth of the telecommunications industry towards the end of the 20th century, primarily due to the introduction of digital signal processing in wireless communications, driven by the development of low-cost, very large-scale integration (VLSI) RF CMOS technology. It enabled sophisticated, low-cost and portable end-user terminals, and gave rise to small, low-cost, low-power and portable units for a wide range of wireless communication systems. This enabled "anytime, anywhere" communication and helped bring about the wireless revolution, leading to the rapid growth of the wireless industry. In the early 2000s, RF CMOS chips with deep sub-micron MOSFETs capable of over 100 GHz frequency range were demonstrated. As of 2008, the radio transceivers in all wireless networking devices and modern mobile phones are mass-produced as RF CMOS devices.

Applications

The baseband processors and radio transceivers in all modern wireless networking devices and mobile phones are mass-produced using RF CMOS devices. RF CMOS circuits are widely used to transmit and receive wireless signals, in a variety of applications, such as satellite technology (including GPS and GPS receivers), Bluetooth, Wi-Fi, near-field communication (NFC), mobile networks (such as 3G and 4G), terrestrial broadcast, and automotive radar applications, among other uses. Examples of commercial RF CMOS chips include Intel's DECT cordless phone, and 802.11 (Wi-Fi) chips created by Atheros and other companies. Commercial RF CMOS products are also used for Bluetooth and Wireless LAN (WLAN) networks. RF CMOS is also used in the radio transceivers for wireless standards such as GSM, Wi-Fi, and Bluetooth, transceivers for mobile networks such as 3G, and remote units in wireless sensor networks (WSN). RF CMOS technology is crucial to modern wireless communications, including wireless networks and mobile communication devices. One of the companies that commercialized RF CMOS technology was Infineon. Its bulk CMOS RF switches sells over 1 billion units annually, reaching a cumulative 5 billion units, as of 2018. Practical software-defined radio (SDR) for commercial use was enabled by RF CMOS, which is capable of implementing an entire software-defined radio system on a single MOS IC chip. RF CMOS began to be used for SDR implementations during the 2000s.

Common applications

RF CMOS is widely used in a number of common applications, which include the following.

See also

References

Illustrations

RF CMOS: Die shot of a Broadcom BCM2050KMLG, an RF CMOS chip used as a WiFi 802.11g transceiver.[1] Notice the octagon-like, spiral-like structures, which can act as inductors[2] transformers and baluns.[3][4][5]
Die shot of a Broadcom BCM2050KMLG, an RF CMOS chip used as a WiFi 802.11g transceiver.[1] Notice the octagon-like, spiral-like structures, which can act as inductors[2] transformers and baluns.[3][4][5]
RF CMOS: Die shot of a Marvell 88W8010 WiFi 802.11g transceiver. It has both octagon-like and square-like, spiral-like structures that can also be used as inductors.[6]
Die shot of a Marvell 88W8010 WiFi 802.11g transceiver. It has both octagon-like and square-like, spiral-like structures that can also be used as inductors.[6]
RF CMOS: Asad Ali Abidi developed RF CMOS technology at UCLA during the late 1980s to early 1990s.
Asad Ali Abidi developed RF CMOS technology at UCLA during the late 1980s to early 1990s.
RF CMOS: The ESP32 is an example of a chip combining RF CMOS with digital logic, which in this case is one or two processor cores that are hidden under the power delivery layer covering most of the image.
The ESP32 is an example of a chip combining RF CMOS with digital logic, which in this case is one or two processor cores that are hidden under the power delivery layer covering most of the image.

Worked examples

Example 1 — a first encounter with RF CMOS

Start with the simplest possible case. Write down what RF CMOS claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to RF CMOS before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about RF CMOS ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of RF CMOS

In research
RF CMOS appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses RF CMOS in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
RF CMOS is common in secondary-school and first-year university syllabi. It links to neighbouring topics Digital electronics, Electronic design, Integrated circuits, so understanding it makes those chapters shorter.
In everyday life
Look for RF CMOS outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study RF CMOS in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what RF CMOS means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain RF CMOS out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is RF CMOS in simple terms?

RF CMOS is a metal–oxide–semiconductor (MOS) integrated circuit (IC) technology that integrates radio-frequency (RF), analog and digital electronics on a mixed-signal CMOS (complementary MOS) RF circuit chip. It is widely used in modern wireless telecommunications, such as cellular networks, Blueto…

Why does RF CMOS matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study RF CMOS?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on RF CMOS.

Tags

  • Digital electronics
  • Electronic design
  • Integrated circuits
  • MOSFETs
  • Pakistani inventions

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