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CN-122001318-A - Adjustable MMIC band-pass filter based on tap inductance technology

CN122001318ACN 122001318 ACN122001318 ACN 122001318ACN-122001318-A

Abstract

The invention discloses an adjustable MMIC band-pass filter based on a tap inductance technology, which comprises a radio frequency input end, a radio frequency output end, a low-pass filter circuit and an adjustable band-pass filter circuit, wherein the low-pass filter circuit and the adjustable band-pass filter circuit are connected in series between the radio frequency input end and the radio frequency output end, the low-pass filter circuit comprises a first capacitor, a second capacitor, a third network, a fourth network, a fifth adjustable capacitor and a sixth adjustable capacitor, one end of the inductor is connected with the radio frequency input end, the other end of the inductor is coupled with the first network, the first network and the second network are coupled through the fifth adjustable capacitor, the second network and the third network are coupled through the tap inductance, the third network and the fourth network are coupled through the sixth adjustable capacitor, and the fourth network is connected with the radio frequency output end. The invention realizes compact magnetic coupling by utilizing the tap inductance technology, remarkably reduces the insertion loss and the chip area, and simultaneously realizes wide tuning range and high harmonic suppression.

Inventors

  • LIN RUI
  • FENG CHENG
  • JIANG XIN

Assignees

  • 南京米乐为微电子科技股份有限公司

Dates

Publication Date
20260508
Application Date
20251205

Claims (7)

  1. 1. The adjustable MMIC band-pass filter based on the tap inductance technology is characterized by comprising a radio frequency input end, a radio frequency output end, a low-pass filter circuit and an adjustable band-pass filter circuit which are connected in series between the radio frequency input end and the radio frequency output end; the adjustable band-pass filter circuit comprises a first network, a second network, a third network, a fourth network, a fifth adjustable capacitor C 5 and a sixth adjustable capacitor C 6 ; One end of an inductor L L1 is connected with the radio frequency input end, and the other end of the inductor L L1 is connected with the first network in a coupling way; The first network and the second network are coupled through a fifth adjustable capacitor C 5 , the second network and the third network are coupled through tap inductance, the third network and the fourth network are coupled through a sixth adjustable capacitor C 6 , and the fourth network is connected with the radio frequency output end.
  2. 2. The tunable MMIC band-pass filter according to claim 1, wherein one end of the inductor L L1 is connected to one end of the first capacitor C L1 , one end of the third capacitor C L3 , and the radio frequency input end, respectively, the other end of the inductor L L1 is connected to one end of the second capacitor C L2 , the other end of the third capacitor C L3 , and the first network, respectively, and the other end of the first capacitor C L1 is connected to the other end of the second capacitor C L2 and grounded.
  3. 3. The tunable MMIC bandpass filter based on tap inductance technology according to claim 1, wherein the first network comprises a first tunable capacitor C 1 and a first tap inductance L 1 , the second network comprises a third tunable capacitor C 3 and a third tap inductance L 3 , the third network comprises a fourth tunable capacitor C 4 and a fourth tap inductance L 4 , and the fourth network comprises a second tunable capacitor C 2 and a second tap inductance L 2 ; One end of the first adjustable capacitor C 1 is respectively connected with one end of the second adjustable capacitor C 2 , one end of the third adjustable capacitor C 3 and one end of the fourth adjustable capacitor C 4 and grounded, and the other end of the first adjustable capacitor C 1 is respectively connected with one end of the first tap inductor L 1 , one end of the fifth adjustable capacitor C 5 is connected, the other end of the third adjustable capacitor C 3 is respectively connected with one end of the third tap inductor L 3 and the other end of the fifth adjustable capacitor C 5 , and the other end of the fourth adjustable capacitor C 4 is respectively connected with one end of the fourth tap inductor L 4 , One end of the sixth adjustable capacitor C 6 is connected, the other end of the second adjustable capacitor C 2 is respectively connected with one end of the second tap inductor L 2 and the other end of the sixth adjustable capacitor C 6 , and the other end of the first tap inductor L 1 is respectively connected with the other end of the second tap inductor L 2 , The other end of the third tap inductor L 3 and the other end of the fourth tap inductor L 4 are connected to the ground, and the tap end of the third tap inductor L 3 is connected to the tap end of the fourth tap inductor L 4 .
  4. 4. A tunable MMIC bandpass filter based on tapped-inductor technology according to claim 3, characterized in that the other end of the inductor L L1 is connected to the tap end of the first tapped inductor L 1 .
  5. 5. A tunable MMIC bandpass filter based on tapped-inductor technology according to claim 3, characterized in that the tap of the second tapped-inductor L 2 is connected to the radio-frequency output.
  6. 6. A tunable MMIC bandpass filter based on tapped-inductor technology according to claim 3, characterized in that the tunable capacitance comprises a first varactor C v1 , a second varactor C v2 , a first resistor R 1 and a voltage control port V con ; The positive electrode of the first varactor C v1 is used as one end of an adjustable capacitor, the negative electrode of the first varactor C v1 is connected with the negative electrode of the second varactor C v2 , the positive electrode of the second varactor C v2 is used as the other end of the adjustable capacitor, one end of the first resistor R 1 is connected with the negative electrode of the first varactor C v1 , and the other end of the first resistor R 1 is connected with the voltage control port V con ; The voltage control ports V con of the first to sixth tunable capacitors C 1 ~C 6 are connected to the same control voltage.
  7. 7. A tunable MMIC bandpass filter based on tap inductance technology according to claim 3, characterized in that the first tap inductance L 1 is coupled to the third tap inductance L 3 , the second tap inductance L 2 is coupled to the fourth tap inductance L 4 , the two coupling coefficients are the same or different, and the coupling coefficient can be 0.

Description

Adjustable MMIC band-pass filter based on tap inductance technology Technical Field The invention relates to the technical field of band-pass filter design, in particular to an adjustable MMIC band-pass filter based on a tap inductance technology. Background With the rapid evolution of applications such as 5G/6G multiband communications, software defined radio and broadband electronic reactance, the radio frequency front end has placed more stringent demands on "small-size, single-voltage, continuously tunable" bandpass filters. The traditional implementation scheme mainly comprises four types, namely 1, a switched capacitor array, namely a discrete capacitor is switched through a CMOS/SOI switch to realize frequency hopping, and the defects of the traditional implementation scheme are complex control and low Q value. 2. Q-enhancement active filter-using negative resistors to counteract passive device losses, obtaining tunable bandwidth, which has the disadvantage of introducing active noise and deteriorating linearity. 3. The N path filter realizes LO tracking filtering by means of a baseband-switch time-varying resistor shifting principle, and has the defects of dependence on a multiphase high-frequency clock and poor high-frequency band out-of-band rejection. 4. The direct tuning of the pure varactor, the continuous change of the reverse junction capacitance by single voltage, has simple structure, and has the defects of needing a large area of inductor/transformer to complete resonator coupling and limited integration level. The scheme has the characteristics of small chip area, low control complexity, low insertion loss, high out-of-band rejection and the like, and is difficult to meet the requirements of a tunable filter with higher performance. In addition, along with the development of the wireless communication system towards the multi-band and high-integration level, the traditional MMIC (Monolithic Microwave Integrated Circuit ) filter structure has the following problems that 1, the multi-band coverage needs a plurality of filters, the area is large, the control is complex, 2, the adjustable filters are controlled by multiple voltages, the complexity of the system is increased, 3, the higher harmonic suppression capability is poor, the requirement of the modern communication system on broadband suppression is difficult to meet, and 4, the traditional magnetic coupling structure (such as a transformer and a coupling inductor) has large area and high loss, and is unfavorable for integration. Disclosure of Invention The invention aims to solve the technical problems of providing an adjustable MMIC band-pass filter based on a tap inductance technology, and the adjustable filter has the characteristics of smaller chip area, low control complexity, low insertion loss, high out-of-band rejection and the like. In order to solve the technical problems, the invention adopts the following technical scheme: An adjustable MMIC band-pass filter based on tap inductance technology comprises a radio frequency input end, a radio frequency output end, a low-pass filter circuit and an adjustable band-pass filter circuit which are connected in series between the radio frequency input end and the radio frequency output end. The low-pass filter circuit comprises first to third capacitors and an inductor, and the adjustable band-pass filter circuit comprises a first network, a second network, a third network, a fourth network, a fifth adjustable capacitor and a sixth adjustable capacitor. One end of the inductor is connected with the radio frequency input end, and the other end of the inductor is connected with the first network in a coupling way. The first network and the second network are coupled through a fifth adjustable capacitor, the second network and the third network are coupled through tap inductance, the third network and the fourth network are coupled through a sixth adjustable capacitor, and the fourth network is connected with the radio frequency output end. Further, one end of the inductor is connected with one end of the first capacitor, one end of the third capacitor and the radio frequency input end respectively, the other end of the inductor is connected with one end of the second capacitor, the other end of the third capacitor and the first network respectively, and the other end of the first capacitor is connected with the other end of the second capacitor and grounded. Further, the first network comprises a first adjustable capacitor and a first tap inductor, the second network comprises a third adjustable capacitor and a third tap inductor, the third network comprises a fourth adjustable capacitor and a fourth tap inductor, and the fourth network comprises a second adjustable capacitor and a second tap inductor; One end of the first adjustable capacitor is connected with one end of the second adjustable capacitor, one end of the third adjustable capacitor and one end of the fourth adjustable cap