Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: Who developed the transistor?
The transistor is the fundamental building block of modern electronic devices, and is ubiquitous in modern electronic systems. Julius Edgar Lilienfeld patented a field-effect transistor in 1926[1] but it was not possible to actually construct a working device at that time. The first practically implemented device was a point-contact transistor invented in 1947 by American physicists John Bardeen, Walter Brattain, and William Shockley. The transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things. The transistor is on the list of IEEE milestones in electronics,[2] and Bardeen, Brattain, and Shockley shared the 1956 Nobel Prize in Physics for their achievement.[3]
The micro-alloy transistor (MAT) was developed by Philco as an improved type of alloy-junction transistor, it offered much higher speed.
Further developments included the grown-junction transistor (1951), the surface-barrier transistor (1953), the diffusion transistor, the tetrode transistor, and the pentode transistor. The diffused silicon 'mesa transistor' was developed at Bell in 1955 and made commercially available by Fairchild Semiconductor in 1958.[32] The spacistor[33] was a type of transistor developed in the 1950s as an improvement over the point-contact transistor and the later alloy junction transistor.
In 1953, whilst still a post-graduate research student at Manchester University, Grimsdale achieved one of the first major landmarks in his career with his design and development work on the Metrovick 950, the world's first computer made from transistors rather than valves or electromechanical devices. The computer used early point-contact transistors which were the first generation of transistors, however later developments of the machine used more advanced junction transistors which offered better performance.
The ballistic collection transistor is the bipolar transistor exhibiting a ballistic conduction resulting in significant velocity overshoot. Initial demonstration of ballistic conduction in gallium arsenide was done in 1985 by IBM researchers. The amplifier with 40 GHz bandwidth based on heterojunction bipolar transistor gallium arsenide technology implementing ballistic collection transistors was developed in 1994 by Nippon Telegraph and Telephone researchers.
Prototypes of all-transistor AM radio receivers were demonstrated, but were really only laboratory curiosities. However, in 1950 Shockley developed a radically different type of solid-state amplifier which became known as the bipolar junction "transistor". Although it works on a completely different principle to the point-contact "transistor", this is the device which is most commonly referred to as simply a "transistor" today. Morgan Sparks made the bipolar junction transistor into a practical device.[18][19] These were also licensed to a number of other electronics companies, including Texas Instruments, who produced a limited run of transistor radios as a sales tool. Early transistors were chemically unstable and only suitable for low-power, low-frequency applications, but as transistor design developed, these problems were slowly overcome.
Fairchild's strategy for competing in the transistor market was to be fast and flexible. Rather than tying their research and development to lengthy 1-3 year military contracts, they financed development through Fairchild Camera. This enabled them to focus on promising ideas and develop them quickly. IBM was interested in obtaining transistors for a navigation computer for the B-70 bomber. Fairchild contracted to provide transistors to meet the specifications for IBM's core-memory driver. They developed complementary NPN and PNP transistors which could be used as a matched pair in a variety of circuit applications. Gordon Moore and David Allison worked on the NPN transistor, while Jean Hoerni developed the PNP transistor using boron diffusion. Scaling up to production of components in quantity presented major technological challenges, and Moore's NPN transistor was ready for production before Hoerni's PNP transistor. By August 1958, within 8 months of the company's creation, Fairchild was delivering Mesa transistors to IBM. Once it became available, the mesa transistor was desired for a wide variety of military applications. The speed with which it had been developed gave Fairchild a virtual monopoly on the fast-growing market for the next year. The most significant contract came from Autonetics, which was developing the navigation and control computer for the Minuteman ICBM.
Historically, designers frequently used the "quasi-complementary" configuration, which uses a Darlington push pair (i.e., two NPN transistors) and a Sziklai pull pair (i.e., one PNP and one NPN transistor). This configuration, which uses three NPN transistors and one PNP transistor, is advantageous because while the first transistors and the most common small signal transistors for decades were PNP germanium devices, silicon PNP power transistors were slower to develop than and have historically been more expensive than their NPN counterparts. Alternately, if a germanium PNP device were used, it would have significantly different characteristics. In the quasi-complementary topology, the performance of the lower pull pair, which used a single NPN transistor, more closely matched the performance of the upper push pair, which consists of two NPN transistors and an identical power device.
In 1953, Philco had developed the world's first high frequency surface-barrier transistor, which was also the first transistor that was suitable for high speed computers.[34] The world's first all-transistor car radio, manufactured by Philco in 1955, used surface-barrier transistors in its circuitry design.[35][36]
Turner was involved with creating the 1N34A germanium diode at Sylvania in the 1940s. He began experimenting with germanium transistors soon after their invention in 1947. In 1949, before transistors were commercially available, he published the popular article "Build a Transistor", considered a "benchmark publication" in amateur radio. In January 1950, after commercial units were released, he published "A Crystal Receiver with Transistor Amplifier" in "Radio and Television News", along with plans for a three-transistor radio circuit. These plans – printed four years before the Regency TR-1 (the first commercial transistor radio) – were the first time most amateur radio operators were introduced to transistors as viable radio components. He continued development of his pocket-size radios as superior transistors became available, culminating in the 'widely read' "Transistor Portable with a "Punch"", an 'ambitious' four-transistor non-superheterodyne AM radio published in "Popular Electronics" in 1956.
The magnetically sensitive transistor (also known as the spin transistor or spintronic transistor—named for spintronics, the technology which this development spawned), originally proposed in 1990 by Supriyo Datta and Biswajit Das, currently still being developed, is an improved design on the common transistor invented in the 1940s. The spin transistor comes about as a result of research on the ability of electrons (and other fermions) to naturally exhibit one of two (and only two) states of spin: known as "spin up" and "spin down". Thus, spin transistors operate on electron spin as embodying a two-state quantum system. Unlike its namesake predecessor, which operates on an electric current, spin transistors operate on electrons on a more fundamental level; it is essentially the application of electrons set in particular states of spin to store information.
The germanium alloy-junction transistor, or alloy transistor, was an early type of bipolar junction transistor, developed at General Electric and RCA in 1951 as an improvement over the earlier grown-junction transistor.
The post-alloy diffused transistor (PADT), or post-alloy diffused-base transistor, was developed by Philips (but GE and RCA filed for patent and Jacques Pankove of RCA received patent for it) as an improvement to the germanium alloy-junction transistor, it offered even higher speed. It is a type of diffused-base transistor.
The world’s first transistor computer was built at the University of Manchester in November 1953. The computer was built by Richard Grimsdale, then a research student in the Department of Electrical Engineering and later a Professor of Electronic Engineering at Sussex University. The machine used point-contact transistors, made in small quantities by STC and Mullard. These consisted of a single crystal of germanium with two fine wires, resembling the crystal and cat’s whisker of the 1920s. These transistors had the useful property that a single transistor could possess two stable states. ... The development of the machine was severely hampered by the unreliability of the transistors, which consumed 150 watts.[27]
The spacistor was a type of transistor developed in the 1950s as an improvement over the point-contact transistor and the later alloy junction transistor. It offered much higher speed than earlier transistors. It became obsolete in the early 1960s with the development of the diffusion transistor.
There were two types of tetrode transistor developed in the early 1950s as an improvement over the point-contact transistor and the later grown junction transistor and alloy junction transistor. Both offered much higher speed than earlier transistors.
Tanenbaum made significant contributions in the fields of transistor development and semiconductor manufacturing. 
Although it was not made public at the time, he developed the first silicon transistor, demonstrating it on January 26, 1954 at Bell Labs. He also helped develop the first gas-diffused silicon transistor, which convinced Bell administrators to support the use of silicon over germanium in their transistor design. He later led a team that developed the first high-field superconducting magnets.
The development of transistors in 1948 by Bell Laboratories led to major improvements to the hearing aid. The transistor was invented by John Bardeen, Walter Brattain, and William Shockley. Transistors were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. These vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement.The 1952 Sonotone 1010 used a transistor stage along with vacuum tubes, to extend battery life. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items, even eyeglasses. In 1951, Raytheon manufactured the transistor and was one of the first companies to mass-produce transistors to throughout America. Raytheon realized that their hearing aid only lasted short-term and began to sell the vacuum-tube hearing aids again along with transistor hearing aids.
Transistor laser is a semiconductor device that functions as a transistor with an electrical output and an optical output as opposed to the typical two electrical outputs. This optical output separates it from typical transistors and, because optical signals travel faster than electrical signals, has the potential to speed up computing immensely. Researchers who discovered the transistor laser developed a new model of Kirchhoff's current law to better model the behavior of simultaneous optical and electrical output.
The Philco Transac models S-1000 scientific computer and S-2000 electronic data processing computer were early commercially produced large-scale all-transistor computers; they were announced in 1957 but did not ship until sometime after the fall of 1958. The Philco computer name "Transac" stands for Transistor-Automatic-Computer. Both of these Philco computer models used the surface-barrier transistor in their circuitry designs, the world's first high-frequency transistor suitable for high-speed computers. The surface-barrier transistor was developed by Philco in 1953.
The world's first all-transistor car radio, was developed and produced by Chrysler and Philco in 1955. Chrysler offered this all-transistor car radio, Mopar model 914HR, available as an "option" in the fall of 1955, for its new line of 1956 Chrysler and Imperial cars. Philco was the manufacturer of these all-transistor car radios for the Chrysler Corporation and had also used its surface-barrier transistors in the radio's circuitry design.
The final step in the development process, starting in the 1980s and continuing through the present, was "very-large-scale integration" (VLSI). The development started with hundreds of thousands of transistors in the early 1980s, , transistor counts continue to grow beyond ten billion transistors per chip.
Microstrip, a type of transmission line usable at microwave frequencies, was invented with printed circuits in the 1950s. The ability to cheaply fabricate a wide range of shapes on printed circuit boards allowed microstrip versions of capacitors, inductors, resonant stubs, splitters, directional couplers, diplexers, filters and antennas to be made, thus allowing compact microwave circuits to be constructed. 
Transistors that operated at microwave frequencies were developed in the 1970s. The semiconductor gallium arsenide (GaAs) has a much higher electron mobility than silicon, so devices fabricated with this material can operate at 4 times the frequency of similar devices of silicon. Beginning in the 1970s GaAs was used to make the first microwave transistors, and it has dominated microwave semiconductors ever since. MESFETs (metal-semiconductor field-effect transistors), fast GaAs field effect transistors using Schottky junctions for the gate, were developed starting in 1968 and have reached cutoff frequencies of 100 GHz, and are now the most widely used active microwave devices. Another family of transistors with a higher frequency limit is the HEMT (high electron mobility transistor), a field effect transistor made with two different semiconductors, AlGaAs and GaAs, using heterojunction technology, and the similar HBT (heterojunction bipolar transistor).
The surface-barrier transistor became obsolete in the early 1960s with the development of the planar diffusion transistor.
The micro-alloy diffused transistor (MADT), or micro-alloy diffused-base transistor, was developed by Philco as an improved type of micro-alloy transistor; it offered even higher speed. It is a type of diffused-base transistor.