Method for improving high-frequency stability of heterojunction bipolar transistor (HBT)

Abstract

The invention discloses a method for improving the high-frequency stability of a heterojunction bipolar transistor (HBT). The method comprises the following steps of: 1) selecting an HBT device with a frequency point fK=1 which is greater than 1 GHz and of which a K stable factor is 1; (2) constructing a co-emitter mixed PI-type small signal model of the HBT device, and acquiring a relational expression of a small signal parameter and the epitaxial layer parameter and size structural parameter of the device by using the small signal model; (3) acquiring an optimized parameter meeting an optimized target according to a high-frequency stability design requirement, a high-frequency gain requirement of a circuit and the relational expression acquired in the step (2); and (4) reducing the frequency point fK=1 of which the K stable factor is 1 and expanding the unconditional stable bandwidth of the HBT device by using the optimized parameter and the relational expression acquired in the step (2), thus improving the high-frequency stability. According to the method, the stability design of an amplifier is realized, and an external stable network is saved, thus the whole performance of the circuit is improved.

Description

technical field [0001] The invention belongs to the field of research and development of high-frequency semiconductor devices and integrated circuits, and in particular relates to a method for improving the high-frequency stability of HBT. Background technique [0002] Due to the huge demand in wireless applications such as wireless communication, radar, electronic countermeasures, remote sensing and telemetry, radio frequency identification system (RFID), wireless sensor network (wsn), the market for radio frequency and microwave amplifier integrated circuits is developing very rapidly. Heterojunction bipolar junction transistor (HBT) has become one of the mainstream technologies for developing radio frequency and microwave amplifiers due to its high frequency characteristics, high power density, high work efficiency, good linearity, and single power supply. When developing radio frequency and microwave amplifier circuits, HBT devices are required to have good high frequenc...

AI Technical Summary

Problems solved by technology

[0004] 1) For a monolithic integrated circuit, the lossy network will occupy a large chip area and increase the cost of the chip;

[0005] 2) The values ​​of components such as resistors, capacitors, and inductors in the stable network have large dispersion, which leads to a greater impact on the stability of the network by the manufacturing process. Especially for power amplifier modules, the external network is far away from the internal feedback loop of the device. The frequency-time discrete lossy network components themselves will introduce parasitic parameters, resulting in a decrease in the stability of the lossy network, or even failure;

[0006] 3) The general network is located on the radio frequency signal path, so the power gain and output power of the power device will be reduced to a certain extent, and the value of the network element must be carefully selected to reduce the impact on device performance

[0007] It can be seen that there are many deficiencies in improving the stability of the power amplifier by adding a lossy stabilization network, so it is necessary to adopt a new method to improve the stability of the device

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