Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas
  • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/12—Supports; Mounting means
  • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
  • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
  • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
  • H01Q1/242—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
  • H04B1/06—Receivers
  • H04B1/16—Circuits
  • H04B1/18—Input circuits, e.g. for coupling to an antenna or a transmission line

Definitions

• the present invention relates to a high impedance type high frequency antenna, and in particular, to an improved high impedance type high frequency antenna by which the antenna is not influenced by an external factor when a human body or the like approaches the antenna by enabling a high impedance by decreasing a reactance component and increasing a resistance component, whereby it is possible to fabricate a compact size product.
• the conventional antenna of a mobile phone, a wireless phone, a PCS (Personal Communication System), or the like is lengthy, thus causing inconvenience. Therefore, it is needed to fabricate a shorter antenna of the system.
• the resistance R should be preferably 250 ⁇ , and the reactance X should be preferably -350—450.
• the antenna is easily influenced when a human body or the like approaches the same due to the resistance R and the reactance X, thus degrading the SWR (Standing Wave Ratio) and an antenna characteristic, whereby the lengthy of the antenna of a high frequency broad band wireless instrument becomes about 16-18 cm.
• FIGs 1 through 4 are schematic diagrams illustrating conventional antennas. As shown therein, there are known four kinds of loading type antennas in which 1/2 ⁇ and 1/4 ⁇ are used.
• the helical antenna of 1/4 ⁇ and the monopole antenna of 1/2 ⁇ monopole antenna of 1/2 ⁇ is generally used.
• the capacity of antenna is indicated as a R and jX, and in the monopole antenna of 1/2 ⁇ , the value of R is 200-300 ⁇ , and the value of X is -300— 400 ⁇ .
• the monopole antenna has a lower resistance (R: 200-300 ⁇ ) and a reactance component (X: -300—400 ⁇ ), the antenna is influenced when a human body or the like approaches the same.
• a high impedance type high frequency antenna which includes an RF module having an input and output capacity of 50 ⁇ , and a matching circuit connected between the antenna and the RF module for outputting 50 ⁇ of an impedance and having a smith chart at a 1/4 ⁇ helical portion so that a 1/2 ⁇ monopole antenna is matched with a 50 ⁇ RF module
• the matching circuit includes a condenser having a capacity of 1 PF and an inductor having a capacity of 18mH, and the impedance of the 1/2 ⁇ monopole is 400-500 ⁇ , and a reactance of the same is 0,
• the matching circuit includes a condenser having a capacity of 1PF and an inductor having a capacity of 18mH, and the impedance of the 1/2 ⁇ monopole is 400-500 ⁇ , and the reactance of the same is 0.
• FIGS. 1 through 4 are schematic diagrams illustrating the constructions of conventional antennas
• FIG. 5 is a schematic diagram illustrating the construction of a high impedance type high frequency antenna according to the present invention
• Figure 6 is a detailed circuit diagram illustrating a matching circuit according to the present invention
• Figure 7 is a diagram illustrating a smith chart according to the present invention.
• Figures 8A through 8C are front views illustrating the construction of an antenna according to the present invention, of which: Figure 8A is a front view illustrating an antenna according to the present invention;
• Figure 8B is a front view illustrating an inductor according to the present invention.
• Figure 8C is a front view illustrating a condenser according to the present invention.
• FIG. 5 illustrates the construction of a high impedance type high frequency antenna according to the present invention.
• the high impedance type high frequency antenna according to the present invention includes an RF module 10 having an input and output capacity of 50 ⁇ , an antenna 20 for receiving and transmitting signals, and a matching circuit 30 connected between the antenna 20 and the RF module for outputting 50 ⁇ of the impedance of the antenna so that the signal from the antenna 20 is made identical to the impedance of the RF module 10.
• FIG. 6 illustrates a matching circuit according to the present invention. As shown therein, a condenser C10 of 1pF and an inductor L10 of a 18mH are connected.
• Figure 7 illustrates a smith chart according to the present invention
• Figures 8A through 8C illustrate the construction of an antenna according to the present invention, of which:
• Figure 8A is a front view illustrating an antenna according to the present invention
• Figure 8B is a front view illustrating an inductor according to the present invention
• Figure 8C is a front view illustrating a condenser according to the present invention.
• points A through C denote impedance flowing paths. Namely, such points are impedance regions in which there is not a reactance component, and the resistance component is
• the output from the RF module 10 is 50 ⁇ , the output is related to the point B in the smith chart.
• the parallel condenser of an admittance chart and the serial inductor of an impedance chart are further needed.
• the condenser C10 having a capacity of 1pF and the inductor L10 having a capacity of 18mH are needed.
• the integer values may be varied based on the various environment during the experiment or test.
• the high impedance of the antenna is matched with the RF module output impedance of the matching circuit 30.
• the monopole antennas of the 1/4 ⁇ and 1/2 ⁇ are made shorter, and the antenna is not influenced by the human body or the like by using a high impedance antenna.
• the 1/2 ⁇ monopole portion becomes a high impedance by using an LC matching circuit of the helical antenna portion of 1/4 ⁇ , and the 1/4 ⁇ helical antenna becomes a matching circuit.
• the antenna is not influenced by the human or the like by decreasing the reactance component and increasing the resistance component, for thus forming a high impedance state, and it is possible to fabricate an antenna having a lengthy of about 8- 10cm, whereby it is possible to fabricate a compact size product.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Details Of Aerials (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19503432

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (2)

Citations (6)

• 1997
  • 1997-04-21 KR KR1019970014726A patent/KR19980077560A/ko not_active Application Discontinuation
  • 1997-05-27 BR BR9715003-7A patent/BR9715003A/pt not_active Application Discontinuation
  • 1997-05-27 EP EP97925312A patent/EP0981840A1/en not_active Withdrawn
  • 1997-05-27 JP JP10545496A patent/JP2000512118A/ja active Pending
  • 1997-05-27 AU AU30491/97A patent/AU3049197A/en not_active Abandoned
  • 1997-05-27 WO PCT/KR1997/000096 patent/WO1998048478A1/en not_active Application Discontinuation
  • 1997-05-27 CN CN97181995.5A patent/CN1249071A/zh active Pending
  • 1997-05-27 IL IL13106597A patent/IL131065A0/xx unknown

Patent Citations (6)

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