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CN-122029741-A - Low-power millimeter wave multiphase inductance coupling ring oscillator

CN122029741ACN 122029741 ACN122029741 ACN 122029741ACN-122029741-A

Abstract

A multiphase oscillator circuit is disclosed. According to one aspect, a multiphase oscillator circuit for a millimeter wave (mmW) transceiver is provided. The multiphase oscillator circuit includes a plurality of inductively coupled ring oscillators, each of the inductively coupled ring oscillators including a plurality of single stage active delay cells, an output of each of the plurality of inductively coupled ring oscillators being inductively coupled to an output of another of the plurality of inductively coupled ring oscillators.

Inventors

  • I.U.Ding
  • H. Sjorand
  • F Torres
  • ZOU GANG

Assignees

  • 瑞典爱立信有限公司

Dates

Publication Date
20260512
Application Date
20231016

Claims (20)

  1. 1. A multiphase oscillator circuit (100) for a millimeter wave mmW transceiver, the multiphase oscillator circuit (100) comprising: A plurality of inductively coupled ring oscillators (102, 104), each inductively coupled ring oscillator (102, 104) comprising a plurality of single stage active delay cells (106), an output of each of the plurality of inductively coupled ring oscillators (102, 104) being inductively coupled to an output of another of the plurality of inductively coupled ring oscillators (102, 104).
  2. 2. The multiphase oscillator circuit (100) of claim 1 further comprising a center tapped differential inductor (108) configured to inductively couple the outputs of a pair of inductively coupled ring oscillators (102, 104).
  3. 3. The multiphase oscillator circuit (100) of claim 2, wherein a center tap of the center tap differential inductor (108) is connected to signal ground via a first capacitor (110).
  4. 4. The multiphase oscillator circuit (100) of any one of claims 1 to 3 further comprising a second capacitor (112, 122) for each of the plurality of outputs, the second capacitor (112, 122) configured to set an operating frequency of the multiphase oscillator circuit (100).
  5. 5. The multiphase oscillator circuit (100) of claim 4, wherein a capacitance of said second capacitor (112, 122) is variable.
  6. 6. The multiphase oscillator circuit (100) of any one of claims 1 to 5, wherein the plurality of inductively coupled ring oscillators (102, 104) are configured to generate signals that are separated by the same phase difference.
  7. 7. The multiphase oscillator circuit (100) of claim 6, wherein the number of stages of each inductively coupled ring oscillator (102, 104) of the plurality of inductively coupled ring oscillators (102, 104) is 3 and the same phase difference is 60 degrees.
  8. 8. The multiphase oscillator circuit (100) of any one of claims 1 to 7, wherein the number of inductively coupled ring oscillators (102, 104) is 2.
  9. 9. The multiphase oscillator circuit (100) of any one of claims 1 to 8, wherein each inductively coupled ring oscillator (102, 104) comprises two single ended single stage active delay cells (106).
  10. 10. The multiphase oscillator circuit (100) of any one of claims 1 to 9, wherein the inductively coupled outputs of the two inductively coupled ring oscillators (102, 104) are substantially 180 degrees apart in phase, the phase separation being obtained using passive components.
  11. 11. The multiphase oscillator circuit (100) of any one of claims 1 to 10, further comprising a variable supply voltage configured to enable tuning of the plurality of inductively coupled ring oscillators (102, 104).
  12. 12. A multiphase oscillator circuit (100), comprising: Three differential inductors (108), and Three pairs of active inverters (114), each active inverter (114) of a pair having an output, the outputs of the pair of active inverters (114) being inductively coupled by one of the three differential inductors (108).
  13. 13. The multiphase oscillator circuit (100) of claim 12, wherein each differential inductor (108) is center tapped, the center tap being connected to signal ground via a first capacitor (110).
  14. 14. The multiphase oscillator circuit (100) of any one of claims 12 and 13, wherein the multiphase oscillator circuit (100) has only passive components except for the active inverter (114).
  15. 15. The multiphase oscillator circuit (100) of any one of claims 12 to 14, wherein each active inverter (114) is configured to have an input-output voltage operating point that is half of a supply voltage of the multiphase oscillator circuit (100).
  16. 16. The multiphase oscillator circuit (100) of any one of claims 12 to 15, wherein each differential inductor (108) is electrically parallel with a corresponding resistor.
  17. 17. The multiphase oscillator circuit (100) of any one of claims 12 to 16, wherein each differential coupled inductor (108) is center tapped and each center tap is connected to a common mode resistor.
  18. 18. The multiphase oscillator circuit (100) of any one of claims 12 to 17, wherein an output of each active inverter (114) is coupled to a differential inductor and a variable parallel capacitance.
  19. 19. The multiphase oscillator circuit (100) of any one of claims 12 to 18, wherein each active inverter (114) is configured to introduce a 120 degree phase shift between an input of the active inverter (112) and an output of the active inverter (112).
  20. 20. The multiphase oscillator circuit (100) of any one of claims 12 to 19, wherein each differential inductor (108) is configured to introduce a 180 degree phase shift between the outputs of a pair of the active inverters (114).

Description

Low-power millimeter wave multiphase inductance coupling ring oscillator Technical Field The present disclosure relates to wireless communications, and more particularly to low power millimeter wave (mmWave) multiphase inductively coupled ring oscillators. Background The third generation partnership project (3 GPP) has developed and is developing standards for fourth generation (4G) (also known as Long Term Evolution (LTE)) and fifth generation (5G) (also known as New Radio (NR)) wireless communication systems. Among other features, these systems provide broadband communications between network nodes (e.g., base stations) and mobile Wireless Devices (WDs), as well as communications between network nodes and between WDs. The 3GPP is also developing standards for sixth generation (6G) wireless communication networks. In addition to these standards, the Institute of Electrical and Electronics Engineers (IEEE) has developed and continues to develop standards for other types of wireless communication networks, including Wireless Local Area Networks (WLANs), including wireless fidelity (Wi-Fi) networks and bluetooth networks. WLAN includes wireless communications between Access Points (APs) and non-access point Stations (STAs). Such IEEE standards include IEEE 802.11a/b/g/n/ac/ax and IEEE 802.15. Driven by the increasing data rate requirements, there is a trend to use higher frequencies in wireless and cellular communications. Large bandwidths may be used in the millimeter wave frequency range and are currently being deployed in 5G cellular communication systems. High data rates result in power consumption levels in user equipment becoming too high for certain applications, where the battery becomes too large or must be recharged more frequently. Therefore, a technique of reducing power consumption in the millimeter wave device is required. In millimeter wave receivers, particularly in auxiliary receivers and transmitters that perform tasks to assist the primary transceiver, the difficulty in achieving low power consumption is the generation of millimeter wave multiphase local oscillator signals. For general use in a receiver, a transmitter, and compatibility with other parts of the frequency generation circuit, the signal should preferably have an even number of phases, i.e. differential signal characteristics of a plurality of phases, such that the phase of each generated signal is opposite to the phase of the other generated signal. Two known solutions for multiphase oscillators are discussed. In one known approach, a varactor-free interpolated phase-tuned millimeter wave LC oscillator with multiphase output is proposed. The architecture is shown in fig. 1 and 2 and illustrates one example of a differential ring oscillator topology with a differential LC cavity (tanks) between each differential delay cell stage. Each differential delay cell stage comprises two differential stages in parallel ((transistors M1 and M2 in differential stage 1) and (M3 and M4 in stage 2)). The signal to differential stage 2 is phase shifted by LC-loaded differential stages (M5 and M6). By adjusting the tail current ratio of differential stages 1 and 2, their combined output currents can be phase shifted between output currents that are not phase shifted by the LC-loaded differential stage (i.e., only differential stage 1 has tail current and differential stage 2 has no tail current) and that are phase shifted entirely by the LC-loaded differential stage (i.e., only differential stage 2 has tail current and stage 1 has no tail current). Different tail current ratios will provide a phase shift between the two extremes. By tuning the phase shift of the transconductance in this way, the phase between the voltage and the current in the inter-stage differential LC resonator must be changed accordingly, corresponding to the oscillation frequency variation. As shown in fig. 1, by means of an impedance Z that relates voltage to current, the phase between the current and voltage of the LC resonator is zero at the resonance frequency and shifts as the frequency deviates from resonance. Thus, the oscillation frequency can be tuned by tuning the ratio of the differential pair tail currents, thus eliminating the need for a variable capacitor or inductor. Scaling this design results in a high complexity, for example, for the 6-phase oscillator shown in fig. 1 and 2, it will contain three Gm delay cells, each Gm delay cell having three differential active stages and two LC resonators. Another known circuit is a dual band six-phase voltage controlled oscillator operating between 890MHz and 1080MHz and implemented by 0.18um CMOS technology. It comprises two single ended ring oscillators, each with three delay cells, the corresponding nodes in the two oscillators being connected to each other by a phase shift cell, as shown in fig. 3. The corresponding nodes will then provide signals of opposite phase and the combined oscillator may provide six symme