Radio-frequency power amplifier of mobile communication equipment

• US 6,259,901 B1
• Filed: 12/01/1998
• Issued: 07/10/2001
• Est. Priority Date: 07/03/1998
• Status: Expired due to Fees

• Current Assignee: Korea Mobile Communications Incorporated
• Original Assignee: Korea Mobile Communications Incorporated
• Inventors: Imai, Takeshi, Shinomiya, Yoshitaka
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): West, Lewis G.
• Application Number:
  US09/203,642
• Time in Patent Office: 952 Days
• Field of Search: 455/91, 455/95, 455/115, 455/116, 455/127, 330/65, 330/66, 330/67, 330/68, 330/129, 330/133, 330/134, 330/254, 330/255
• US Class Current: 455/127.3
• CPC Class Codes: H01Q 11/12 Resonant antennas
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control

Abstract

A radio-frequency power amplifier of mobile communication equipment includes a differential amplifier arranged to balanced-input and amplify a radio-frequency signal delivered from a frequency converter of a transmission system of the mobile communication equipment located downstream of a modulator of the transmission system. The radio-frequency signal delivered from the differential amplifier is further amplified and balanced-output by a push-pull circuit. The differential amplifier and the push-pull circuit are respectively supplied with bias currents varying in dependence on a gain control signal, whereby respective amplification gains of the differential amplifier and the push-pull circuit are variably adjusted.

Claims

1. A radio-frequency power amplifier of mobile communication equipment, comprising:

an input stage including at least one differential amplifier arranged to balanced-input and amplify a radio-frequency signal delivered from a frequency converter section of a transmission system of the mobile communication equipment located downstream of a modulator section of the transmission system; and

a bias current circuit for supplying said at least one differential amplifier with a bias current varying in dependence on a gain control signal, to thereby variably set a gain of said at least one differential amplifier, said radio-frequency power amplifier being mounted on a circuit board of the mobile communication equipment, said circuit board being formed with a radio-frequency grounding pattern,

wherein said input stage of said radio-frequency power amplifier amplifies the radio-frequency signal under a floating condition with respect to the radio-frequency grounding pattern.

2. The radio-frequency power amplifier according to claim 1, wherein said input stage of said radio-frequency power amplifier is comprised of a plurality of differential amplifiers which are direct-coupled to one another, and said bias current circuit is provided for each of said plurality of differential amplifiers.

3. The radio-frequency power amplifier according to claim 1, wherein the gain control signal is a signal which is transmitted from a base station or a control section of the mobile communication equipment in order to determine a transmission output level of the mobile communication equipment.

4. The radio-frequency power amplifier according to claim 1, wherein said radio-frequency power amplifier is mounted on the circuit board together with the modulator and frequency converter sections and a receiver system of the mobile communication equipment to thereby constitute a radio-frequency module which serves as a radio-frequency section of the mobile communication equipment.

5. The radio-frequency power amplifier according to claim 4, wherein said radio-frequency power amplifier is configured in a form of an integrated circuit.

6. The radio-frequency power amplifier according to claim 4, wherein said radio-frequency power amplifier is mounted on portable mobile communication equipment.

7. A radio-frequency power amplifier of mobile communication equipment, comprising:

an output stage including a push-pull circuit arranged to amplify and balanced-output a radio-frequency signal received through an input stage of said amplifier from a frequency converter section of a transmission system of the mobile communication equipment located downstream of a modulator section of the transmission system; and

a bias current circuit for supplying said push-pull circuit with a bias current varying in dependence on a gain control signal, said radio-frequency power amplifier being mounted on a circuit board of the mobile communication equipment, said circuit board being formed with a radio-frequency grounding pattern,

wherein said output stage of the radio-frequency power amplifier amplifies the radio-frequency signal under a floating condition with respect to the radio-frequency grounding pattern.

8. The radio-frequency power amplifier according to claim 7, wherein said bias current circuit varies an operating current of a constant current circuit connected with bases of a pair of transistors which form said push-pull circuit, to thereby vary the bias current applied to said push-pull circuit.

9. The radio-frequency power amplifier according to claim 7, wherein the gain control signal is a signal which is transmitted from a base station or a control section of the mobile communication equipment in order to determine a transmission output level of the mobile communication equipment.

10. The radio-frequency power amplifier according to claim 7, wherein said radio-frequency power amplifier is mounted on the circuit board together with the modulator and frequency converter sections and a receiver system of the mobile communication equipment to thereby constitute a radio-frequency module which serves as a radio-frequency section of the mobile communication equipment.

11. The radio-frequency power amplifier according to claim 10, wherein said radio-frequency power amplifier is configured in a form of an integrated circuit.

12. The radio-frequency power amplifier according to claim 10, wherein said radio-frequency power amplifier is mounted on portable mobile communication equipment.

13. A radio-frequency power amplifier of mobile communication equipment, comprising:

an input stage including at least one differential amplifier arranged to balanced-input and amplify a radio-frequency signal delivered from a frequency converter section of a transmission system of the mobile communication equipment located downstream of a modulator section of the transmission system;

a first bias current circuit for supplying said at least one differential amplifier with a bias current varying in dependence on a gain control signal, to thereby variably set a gain of said at least one differential amplifier;

an output stage including a push-pull circuit arranged to receive the radio-frequency signal amplified in and delivered from said input stage and to amplify and balanced-output the amplified radio-frequency signal; and

a second bias current circuit for supplying said push-pull circuit with a bias current varying in dependence on the gain control signal, said radio-frequency power amplifier being mounted on a circuit board of the mobile communication equipment, said circuit board being formed with a radio-frequency grounding pattern,

wherein said input stage and said output stage of said radio-frequency power amplifier amplifies the radio-frequency signal and amplified radio-frequency signal, respectively, under a floating condition with respect to the radio-frequency grounding pattern.

14. The radio-frequency power amplifier according to claim 13, wherein said input stage of said radio-frequency power amplifier is comprised of a plurality of differential amplifiers which are direct-coupled to one another, and said bias current circuit is provided for each of said plurality of differential amplifiers.

15. The radio-frequency power amplifier according to claim 13, wherein said second bias current circuit varies an operating current of a constant current circuit connected with bases of a pair of transistors which form said push-pull circuit, to thereby vary the bias current applied to said push-pull circuit.

16. The radio-frequency power amplifier according to claim 13, wherein the gain control signal is a signal which is transmitted from a base station or a control section of the mobile communication equipment in order to determine a transmission output level of the mobile communication equipment.

17. The radio-frequency power amplifier according to claim 13, wherein said radio-frequency power amplifier is mounted on the circuit board together with the modulator and frequency converter sections and a receiver system of the mobile communication equipment to thereby constitute a radio-frequency module which serves as a radio-frequency section of the mobile communication equipment.

18. The radio-frequency power amplifier according to claim 17, wherein said radio-frequency power amplifier is configured in a form of an integrated circuit.

19. The radio-frequency power amplifier according to claim 17, wherein said radio-frequency power amplifier is mounted on portable mobile communication equipment.