A low-loss on-chip transmission line based on an aperiodic composite left-handed-right-handed structure

Abstract

The application discloses a kind of low-loss on-chip transmission lines based on non-periodic composite left-right hand structure, it is related to radio frequency integrated circuit design technical field, including first radio frequency port, second radio frequency port, M series resonance unit and N parallel resonance unit, each series resonance unit includes series right-hand inductance, left-hand capacitance, each parallel resonance unit includes parallel left-hand inductance, right-hand capacitance;M series resonance unit is in turn connected in series, one end of N parallel resonance unit is in turn loaded between two series resonance units, and the other end of parallel resonance unit is grounded, first radio frequency port is loaded in the free end of first series resonance unit, and second radio frequency port is loaded in the free end of M series resonance unit.The application uses non-periodic lumped transmission line to avoid too large size;While maintaining low loss, echo loss in broadband is all better than 20dB.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radio frequency integrated circuit design, and particularly relates to a low-loss on-chip transmission line based on a non-periodic composite right / left-handed structure. BACKGROUND

[0002] The great demand of modern science and technology society makes the integrated circuit and the radio frequency microwave technology continuously improve and develop rapidly, and various terminal hardware is in great demand, which brings great challenges to the size and performance of the equipment. In this environment, it is naturally the common pursuit of the industry to maintain high performance in the radio frequency band while not sacrificing a certain size.

[0003] The composite right / left-handed (CRLH, composite right / left-handed) transmission line structure, as a classic application design of metamaterial, has various non-traditional characteristics in the left-handed frequency band: negative refractive index, inverse Cherenkov effect, inverse Snell's law, etc. The propagation of the wave on the transmission line shows the opposite parallel phase velocity and group velocity. Taking the classic periodic structure of the composite right / left-handed transmission line as an example, it adopts a distributed effect, achieves the equivalent series inductance and capacitance effect through interdigital capacitors, and realizes the parallel inductance and capacitance through the branch line and the metal via. With the increase of the frequency band, the influence proportion of the right-handed series inductance and step capacitance effect gradually expands to realize the transition from left-handed to right-handed.

[0004] The Chinese patent with the application number CN201210118035.6 discloses a broadband miniaturized dipole antenna based on a composite right / left-handed transmission line, which adopts a non-periodic loading mode, the inductance and capacitance values of each unit are not the same, the number of LC network units is increased, the capacitance and inductance values are adjusted to reduce the working frequency, and the impedance bandwidth is increased. The structure design has strong experience dependence, and the number of units needs to be increased to adjust the bandwidth, but the bandwidth is still only 6.5%; in addition, the return loss near the center frequency is only about 10 dB.

[0005] The Chinese patent with the application number 201410336578.4 discloses an electrically adjustable phase shifter based on a composite right / left-handed transmission line, which realizes a 400° phase shift effect by using the phase shift superposition of the periodic composite right / left-handed unit, but the in-band return loss under different bias voltages of the varactor diode is not uniform, and only part of the frequency band return loss is better than 10 dB.

[0006] Because of the adoption of the parasitic inductance, capacitance and other equivalent series loops of the elements, this often has certain difficulty in the adjustment of LC value. Therefore, researchers have adopted an additional series inductance in the structure of the composite left and right hand to realize the large angle scanning in the narrow band of the leaky wave antenna (a kind of composite left and right hand transmission line type narrow band wide range frequency scanning antenna) to make up for the related defects. However, the in-band performance of the conventional periodic transmission line is not superior under less order, and usually the order is increased to realize the more ideal in-band effect, which means that the loss is further increased. In addition, the self-resonance effect of the distributed structure (such as the interdigital capacitance) is also difficult to avoid.

[0007] Therefore, there is an urgent need for a feasible solution to realize a wider working bandwidth while maintaining a lower loss, and the return loss is better than 20dB in the entire working frequency band. SUMMARY

[0008] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art, and to provide a low-loss patch transmission line based on a non-periodic composite left and right hand structure. The non-periodic lumped transmission line is adopted to avoid oversize; at the same time, based on the non-periodic structure of the present application, by designing the rules, adjusting a certain inductance and capacitance of a specific unit, the return loss in the wide band is better than 20dB while maintaining low loss.

[0009] The present application adopts the following technical solutions to solve the above technical problems:

[0010] According to the low-loss patch transmission line based on the non-periodic composite left and right hand structure provided by the present application, it comprises a first radio frequency port, a second radio frequency port, M series resonance units and N parallel resonance units, wherein N=M-1, and M is an integer greater than 2.

[0011] The M series resonance units comprise first to M series resonance units, and the N parallel resonance units comprise first to N parallel resonance units.

[0012] The i-th series resonance unit comprises a series of i-th right-hand inductance and i-th left-hand capacitance, and the j-th parallel resonance unit comprises a parallel of j-th left-hand inductance and j-th right-hand capacitance; wherein i=1, 2, …, M, j=1, 2, …, N.

[0013] The first to M series resonance units are connected in series, one end of the j-th parallel resonance unit is loaded between the j-th series resonance unit and the j+1-th series resonance unit, the other end of the first to N parallel resonance units is grounded, the first radio frequency port is loaded at the free end of the first series resonance unit, and the second radio frequency port is loaded at the free end of the M series resonance unit.

[0014] The inductance of the kth right-hand inductor is equal to the inductance of the (M-k+1)th right-hand inductor, and the inductance of the 1st to kth right-hand inductor increases with the increase of k; wherein k is an integer and 1<=k<=ceil (M / 2) ;

[0015] The capacitance of the kth left-hand capacitor is equal to the capacitance of the (M-k+1)th left-hand capacitor, and the capacitance of the 1st to kth left-hand capacitor decreases with the increase of k;

[0016] The inductance of the kth ， left-hand inductor is equal to the inductance of the (N-k ， +1)th left-hand inductor, and the inductance of the 1st to kth ， left-hand inductor decreases with the increase of k ， ; wherein k ， is an integer and 1<=k ， <=ceil (N / 2) ;

[0017] The capacitance of the kth ， right-hand capacitor is equal to the capacitance of the (N-k ， +1)th right-hand capacitor, and the capacitance of the 1st to kth ， right-hand capacitor increases with the increase of k ， .

[0018] As a further optimization scheme of the low-loss on-chip transmission line based on the non-periodic composite left-right hand structure, the i th right-hand inductor and the j th left-hand inductor are microstrip line inductance, stripline inductance or spiral inductance, and the i th left-hand capacitor and the j th right-hand capacitor are microstrip line capacitor, metal-oxide-metal capacitor, metal-insulator-metal capacitor or interdigital capacitor.

[0019] As a further optimization scheme of the low-loss on-chip transmission line based on the non-periodic composite left-right hand structure, the other end of the parallel resonant unit is actually connected to the metalized ground via hole, and contains a parasitic effect.

[0020] Compared with the prior art, the above technical scheme has the following technical effects:

[0021] (1) Based on the non-periodic improvement of in-band matching, five transmission poles are uniformly distributed, thereby ensuring that the return loss is better than 20dB in a high frequency band. The problem of high-frequency self-resonance of the periodic distributed structure is avoided, and good return loss is maintained.

[0022] (2) The left-hand high-pass structure in the low frequency band is realized by using the capacitance of the series branch and the inductance of the parallel branch, and the low-pass effect is realized by using the inductance of the series branch and the capacitance of the parallel branch, thereby realizing the effect of wide-band transmission of the left-right hand circuit.

[0023] (3) Based on the composite left-hand and right-hand method, the operating frequency band of the transmission line is widened to a wide band of 15~50GHz, and the -10dB relative bandwidth reaches 112%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an equivalent circuit diagram of the on-chip transmission line provided by the present invention.

[0025] Figure 2 This is a schematic diagram of a fifth-order low-loss on-chip transmission line provided by Example 1 of the present invention.

[0026] Figure 3 It is a simulation curve diagram of the relationship between the scattering parameters and the frequency in Example 1 of the present invention.

[0027] The reference numerals in the figure are explained as follows: P1 is the first RF port, P2 is the second RF port, 1-i is the i-th series resonant unit, 2-j is the j-th parallel resonant unit, L R(i) is the i-th right-hand inductor, C L(i) is the i-th left-hand capacitor, L L(j) is the jth left-hand inductor, C R(j) is the j-th right-hand capacitor. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings:

[0029] Figure 1 Schematic diagram of the circuit designed for the present invention; a low-loss on-chip transmission line based on an aperiodic composite left-handed structure, comprising a first RF port P1, a second RF port P2, M series resonant units, and N parallel resonant units, where N = M-1, and M is an integer greater than 2;

[0030] The M series resonance units include first to M-th series resonance units, and the N parallel resonance units include first to N-th parallel resonance units;

[0031] The i-th series resonant unit 1-i includes an i-th right-handed inductor L connected in series. R(i) , the i-th left-hand capacitor C L(i) The jth parallel resonant unit 2-j includes the jth left-hand inductor L in parallel. L(j) , the jth right-hand capacitor C R(j) ; Where i = 1, 2, ..., M, j = 1, 2, ..., N;

[0032] The first to the Mth series resonance units are connected in series, one end of the jth parallel resonance unit is loaded between the jth series resonance unit and the j+1th series resonance unit, the other end of the first to the Nth parallel resonance units is grounded, the first radio frequency port is loaded at the free end of the first series resonance unit, and the second radio frequency port is loaded at the free end of the Mth series resonance unit;

[0033] The inductance of the kth right-handed inductor is equal to the inductance of the (M-k+1)th right-handed inductor, and the inductance of the first to the kth right-handed inductors increases with the increase of k; wherein k is an integer and 1≤k≤⌈ M / 2⌉;

[0034] The capacitance of the kth left-handed capacitor is equal to the capacitance of the (M-k+1)th left-handed capacitor, and the capacitance of the first to the kth left-handed capacitors decreases with the increase of k;

[0035] The inductance of the kth ， left-handed inductor is equal to the inductance of the (N-k ， +1)th left-handed inductor, and the inductance of the first to the kth ， left-handed inductors decreases with the increase of k ， ; wherein k ， is an integer and 1≤k ， ≤⌈ N / 2⌉ ;

[0036] The capacitance of the kth ， right-handed capacitor is equal to the capacitance of the (N-k ， +1)th right-handed capacitor, and the capacitance of the first to the kth ， right-handed capacitors increases with the increase of k ， .

[0037] The schematic diagram of the embodiment 1 of the present application is shown as Figure 2 follows, a Composite right / left-handed (CRLH) non-periodic on-chip transmission line comprises a first radio frequency port P1, a second radio frequency port P2, 3 right-handed inductors: a first right-handed inductor L R(1) , a second right-handed inductor L R(2) , and a third right-handed inductor L R(3) ; 2 right-handed capacitors: a first right-handed capacitor C R(1) , and a second right-handed capacitor C R(2) ; 2 left-handed inductors: a first left-handed inductor L L(1) , and a second left-handed inductor L L(2) ; and 3 left-handed capacitors: a first left-handed capacitor C L(1) , a second left-handed capacitor C L(2) , and a third left-handed capacitor C L(3); 3 series resonance units: a first series resonance unit 1-1, a second series resonance unit 1-2, and a third series resonance unit 1-3; and 2 parallel resonance units: a first parallel resonance unit 2-1 and a second parallel resonance unit 2-2;

[0038] The first series resonance unit 1-1 is composed of a first right-hand inductor L R(1) , a first left-hand capacitor C L(1) in series, the first parallel resonance unit 2-1 is composed of a first left-hand inductor L L(1) , a first right-hand capacitor C R(1) in parallel, and one end of the first parallel resonance unit is grounded. The first radio frequency port P1 is loaded on the free end of the first series resonance unit 1-1, the second radio frequency port P2 is loaded on the free end of the third series resonance unit 1-3, the first to third series resonance units are connected in sequence, and the first and second parallel resonance units are loaded between two adjacent series resonance units in sequence. R(1) =0.241nH; C L(1) =134fF; L R(2) =0.482nH; C L(2) =67fF; L R(3) =0.241nH; C L(3) =134fF; L L(1) =0.217nH; C R(1) =149fF; L L(2) =0.22nH; C R(2) =149fF.

[0039] Figure 3 is a simulation curve of the scattering parameter and the frequency relationship of the transmission line of the embodiment 1 of the present application. Figure 3 As shown in the figure, the transmission line disclosed in the embodiment 1 of the present application has a center frequency of 28GHz and a working frequency band of 16.5~48GHz. S 11 is the return loss of the input port of the transmission line, there are five transmission poles in the passband, and the return loss in the frequency band is better than 20dB. Compared with the prior art, the transmission line provided in the embodiment 1 of the present application realizes a wider bandwidth and a better return loss.

[0040] The on-chip structure has the advantages of low loss and ultra-wide band, and the non-periodic advantage is that the matching in the frequency band is good, and the return loss can be kept better than 20dB, which makes both of them have great potential in the design of microwave radio frequency devices, integrated circuits and chip design. In addition, the design of loading lumped elements can further reduce the size. In view of this, the present application provides a low-loss on-chip transmission line using a non-periodic composite left-right hand structure, which uses a non-periodic lumped transmission line to avoid excessive size; at the same time, based on the non-periodic structure of the present application, through the design rule, the specific inductance and capacitance of a certain unit are adjusted, while maintaining low loss, the return loss in the wide band is better than 20dB.

[0041] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A low-loss on-chip transmission line based on a non-periodic composite left- right-handed structure, characterized in that, The resonator comprises a first radio frequency port, a second radio frequency port, M serial resonant units and N parallel resonant units, wherein N=M-1, and M is an integer greater than 2; The M serial resonant units comprise first to M serial resonant units, and the N parallel resonant units comprise first to N parallel resonant units; The i-th serial resonant unit comprises an i-th right-handed inductor and an i-th left-handed capacitor in series, and the j-th parallel resonant unit comprises a j-th left-handed inductor and a j-th right-handed capacitor in parallel, wherein i=1, 2, …, M, and j=1, 2, …, N; The first to M serial resonant units are connected in series, one end of the j-th parallel resonant unit is loaded between the i-th serial resonant unit and the i+1-th serial resonant unit, wherein i=j, the other end of the first to N parallel resonant units is grounded, the first radio frequency port is loaded at the free end of the first serial resonant unit, and the second radio frequency port is loaded at the free end of the M serial resonant unit; An inductance of the k-th right-handed inductor is equal to an inductance of the (M-k+1)-th right-handed inductor, and the inductances of the first to k-th right-handed inductors increase with the increase of k, wherein k is an integer and 1≤k≤⌈ M / 2⌉; A capacitance of the k-th left-handed capacitor is equal to a capacitance of the (M-k+1)-th left-handed capacitor, and the capacitances of the first to k-th left-handed capacitors decrease with the increase of k. kth ， The inductance of the left-hand inductor is equal to (N- k ， +1) Inductance of the left-hand inductor, 1st to kth ， The inductance of the left-hand inductor increases with k ， decreases with the increase of ， is an integer and 1≤k ， ≤⌈ N / 2⌉ ; kth ， The capacitance of the right-hand capacitor is equal to (N- k ， +1) the capacitance of the right-hand capacitor, 1st to kth ， The capacitance of the right-hand capacitor increases with k ， increases with the increase of .

2. The low-loss on-chip transmission line based on the non-periodic CRLH structure according to claim 1, characterized in that, The i-th right-handed inductor and the j-th left-handed inductor are microstrip inductors, stripline inductors or spiral inductors, and the i-th left-handed capacitor and the j-th right-handed capacitor are microstrip capacitors, metal-oxide-metal capacitors, metal-insulator-metal capacitors or interdigital capacitors.

3. The low-loss on-chip transmission line based on the non-periodic CRLH structure according to claim 1, characterized in that, The other end of the parallel resonant unit is actually a grounded metalized via hole, and contains a parasitic effect.

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