Designing a standard multilayer circuit board stackup structure for a modern drone counter-UAV system involves far more than arranging copper layers in a pcb board. These electronic platforms integrate radar front-ends, RF amplifiers, digital signal processors, high-speed communication buses, and power regulation stages into a single printed circuit board (PCB). Because of this complexity, engineers often rely on advanced analysis and even reverse engineering of earlier prototype hardware to determine the ideal structure, especially when they must restore or reproduce a proven design without the original Gerber file or layout drawing.
Un apilamiento multicapa adecuado para sistemas antidrones comienza con la identificación de las categorías de señales. Los módulos de radar y detección de radiofrecuencia requieren líneas de transmisión de impedancia controlada, mientras que el procesador principal, la FPGA y las interfaces de comunicación necesitan un enrutamiento denso y de bajo ruido. Los ingenieros evalúan el comportamiento eléctrico del sistema utilizando materiales de referencia o clonando y replicando la estructura subyacente de una placa de circuito impreso existente. Si existe hardware heredado, se puede recuperar un diagrama esquemático, una lista de materiales y una lista de conexiones mediante ingeniería inversa profesional para comprender cómo se dispusieron originalmente las capas. La siguiente etapa consiste en definir la secuencia dieléctrica. Los sistemas antidrones suelen adoptar apilamientos de 6, 8 o 10 capas para separar los dominios analógico, de radiofrecuencia, digital y de potencia. La estructura típica incluye planos de tierra, planos de potencia y capas de señal dedicados, dispuestos simétricamente para minimizar la distorsión. Los ingenieros suelen utilizar una herramienta CAD para crear un archivo CAD que refleje con precisión el grosor del cobre, las constantes dieléctricas y los tipos de resina necesarios para el funcionamiento a alta frecuencia. Si la placa objetivo está destinada a duplicar o modificar un diseño anterior, los nuevos datos Gerber deben mantener la estabilidad de impedancia, la distribución térmica y el aislamiento EMI.
A proper counter-UAV multilayer stackup begins by identifying signal categories. Radar and RF detection modules require controlled-impedance transmission lines, while the main processor, FPGA, and communication interfaces need dense, low-noise routing. Engineers evaluate the system’s electrical behavior using reference materials or by cloning and replicating the underlying structure from an existing electronic circuit board. If legacy hardware exists, a schematic diagram, BOM list, and netlist can be recovered through professional reverse engineering to understand how the layers were originally arranged.
The next stage is defining the dielectric sequence. Counter-drone systems often adopt 6-layer, 8-layer, or 10-layer stackups to separate analog, RF, digital, and power domains. The typical structure includes dedicated ground planes, power planes, and signal layers arranged symmetrically to minimize warping. Engineers frequently use a CAD tool to build a cad file that accurately reflects copper thickness, dielectric constants, and resin types required for high-frequency operation. If the target board is meant to duplicate or modify an earlier design, the new gerber data must maintain impedance stability, thermal distribution, and EMI isolation.
RF layers must be placed next to continuous ground planes to ensure low-loss transmission. This is one of the fundamental design rules for counter-UAV hardware, particularly for jamming transmitters and direction-finding antennas. Engineers may also remanufacture shielding structures by studying via stitching, cavity spacing, and copper islands found during reverse engineering of earlier boards. These details protect sensitive digital layers from the high-power RF signals generated by the jamming module.
Hereby we would like to take an example of a 4 layer circuit board will be described to explain how the arrangement and combination of various Standard Multilayer Circuit Board Stackup Structure are preferred.
For the commonly used 4-layer boards, there are several stacking methods (from top to bottom).
(1) Siganl_1 (Top), GND (Inner_1), POWER (Inner_2), Siganl_2 (Bottom).
(2) Siganl_1 (Top), POWER (Inner_1), GND (Inner_2), Siganl_2 (Bottom).
(3) POWER (Top), Siganl_1 (Inner_1), GND (Inner_2), Siganl_2 (Bottom).
Obviously, the lack of effective coupling between the power layer and the ground plane of scheme 3 should not be adopted.
So how should Option 1 and Option 2 be chosen? In general, the designer will choose option 1 as the structure of the 4-layer board. The reason for the selection is not that Option 2 cannot be used, but that the general PCB board only places components on the top layer, so it is more appropriate to adopt Option 1.
However, when components need to be placed on the top and bottom layers, and the thickness of the medium between the internal power layer and the ground layer is large which will result in bad quality of the coupling, it is necessary to consider which layer has fewer signal lines. For scheme 1, the bottom layer has fewer signal lines, and a large-area copper film can be used to couple with the POWER layer. Conversely, if the components are mainly disposed on the bottom layer, scheme 2 should be used to manufacture printed circuit board.
internal power layer and the ground layer
If the laminated structure shown in Figure 11-1 is used, the power supply layer and the ground layer itself are already coupled. Considering the requirement of symmetry, Scheme 1 is generally adopted.
After the analysis of the laminated structure of the 4-layer board is completed, the arrangement and combination method of the 6-layer board laminated structure and the preferred method will be described below by way of an example of a 6-layer board combination.
(1) Siganl_1 (Top), GND (Inner_1), Siganl_2 (Inner_2), Siganl_3 (Inner_3), POWER (Inner_4), Siganl_4 (Bottom).
Un corretto stackup multistrato anti-UAV inizia con l’identificazione delle categorie di segnale. I moduli radar e di rilevamento RF richiedono linee di trasmissione a impedenza controllata, mentre il processore principale, l’FPGA e le interfacce di comunicazione necessitano di un routing denso e a basso rumore. Gli ingegneri valutano il comportamento elettrico del sistema utilizzando materiali di riferimento o clonando e replicando la struttura sottostante da una scheda elettronica esistente. Se è presente hardware legacy, è possibile recuperare uno schema elettrico, una distinta base (BOM) e una netlist tramite reverse engineering professionale per comprendere la disposizione originale degli strati. La fase successiva è la definizione della sequenza dielettrica. I sistemi anti-drone adottano spesso stackup a 6, 8 o 10 strati per separare i domini analogico, RF, digitale e di potenza. La struttura tipica include piani di massa dedicati, piani di potenza e strati di segnale disposti simmetricamente per ridurre al minimo la deformazione. Gli ingegneri utilizzano spesso uno strumento CAD per creare un file CAD che rifletta accuratamente lo spessore del rame, le costanti dielettriche e i tipi di resina necessari per il funzionamento ad alta frequenza. Se la scheda di destinazione è destinata a duplicare o modificare un progetto precedente, i nuovi dati Gerber devono mantenere la stabilità dell’impedenza, la distribuzione termica e l’isolamento EMI.
Scheme 1 uses four layers of signal layers and two layers of internal power/ground layers. It has more signal layers, which is beneficial to the wiring work between components. However, the defects of this scheme are also obvious, which are manifested in the following two aspects.
1 The power and ground planes are separated far apart and are not fully coupled.
2 The signal layer Siganl_2 (Inner_2) and Siganl_3 (Inner_3) are directly adjacent, and the signal isolation is not good, and crosstalk is easy to occur.
(2) Siganl_1 (Top), Siganl_2 (Inner_1), POWER (Inner_2), GND (Inner_3), Siganl_3 (Inner_4), Siganl_4 (Bottom).
Compared with scheme 1, scheme 2 has sufficient coupling between power layer and ground plane, which has certain advantages over scheme 1, but Siganl_1 (Top) and Siganl_2 (Inner_1) and Siganl_3 (Inner_4) and Siganl_4 (Bottom) signal layers are directly Adjacent, the signal isolation is not good, and the problem of crosstalk is not solved.
(3) Siganl_1 (Top), GND (Inner_1), Siganl_2 (Inner_2), POWER (Inner_3), GND (Inner_4), Siganl_3 (Bottom).
Compared with schemes 1 and 2, scheme 3 reduces one signal layer and adds one inner layer. Although the available wiring level is reduced, the solution solves the defects common to schemes 1 and 2.
Uma configuração adequada de multicamadas para sistemas anti-drones começa com a identificação das categorias de sinal. Módulos de radar e detecção de radiofrequência (RF) requerem linhas de transmissão de impedância controlada, enquanto o processador principal, o FPGA e as interfaces de comunicação necessitam de roteamento denso e de baixo ruído. Os engenheiros avaliam o comportamento elétrico do sistema utilizando materiais de referência ou clonando e replicando a estrutura subjacente a partir de uma placa de circuito eletrônico existente. Caso exista hardware legado, um diagrama esquemático, a lista de materiais (BOM) e a lista de conexões (netlist) podem ser recuperados por meio de engenharia reversa profissional para compreender como as camadas foram originalmente organizadas. A próxima etapa é definir a sequência dielétrica. Sistemas anti-drones frequentemente adotam configurações de 6, 8 ou 10 camadas para separar os domínios analógico, de RF, digital e de energia. A estrutura típica inclui planos de aterramento dedicados, planos de energia e camadas de sinal dispostas simetricamente para minimizar a distorção. Os engenheiros frequentemente utilizam uma ferramenta CAD para criar um arquivo CAD que reflita com precisão a espessura do cobre, as constantes dielétricas e os tipos de resina necessários para a operação em alta frequência. Se a placa de destino se destina a duplicar ou modificar um projeto anterior, os novos dados Gerber devem manter a estabilidade da impedância, a distribuição térmica e o isolamento EMI.
Digital signal layers, especially those handling radar sampling or high-speed command interfaces, require careful routing. Length matching, layer pairing, and reference-plane continuity are essential. Engineers consult the schematic diagram and netlist to determine which traces require differential pair control. To avoid unwanted crosstalk, noisy DC-DC converters or switching elements must be isolated onto separate layers. If the new design intends to reproduce or modify an existing pcb board layout, the improvements often focus on strengthening noise immunity and enhancing thermal paths.
Power planes must also be strategically located. Drone counter-UAV systems drive high-power amplifiers and processors simultaneously, so stable current return paths are necessary. Engineers may clone the original copper pour strategy discovered during reverse engineering of an older printed circuit board to ensure similar performance in the prototype version.
La conception d’une architecture multicouche anti-drone efficace commence par l’identification des catégories de signaux. Les modules de détection radar et RF nécessitent des lignes de transmission à impédance contrôlée, tandis que le processeur principal, le FPGA et les interfaces de communication requièrent un routage dense et à faible bruit. Les ingénieurs évaluent le comportement électrique du système à l’aide de documents de référence ou en clonant et en répliquant la structure sous-jacente d’une carte de circuit imprimé existante. En cas de matériel existant, un schéma, une nomenclature et une netlist peuvent être récupérés par rétro-ingénierie afin de comprendre l’agencement initial des couches. L’étape suivante consiste à définir la séquence diélectrique. Les systèmes anti-drones adoptent souvent des architectures à 6, 8 ou 10 couches pour séparer les domaines analogiques, RF, numériques et d’alimentation. La structure typique comprend des plans de masse, des plans d’alimentation et des couches de signaux dédiés, disposés symétriquement pour minimiser la déformation. Les ingénieurs utilisent fréquemment un logiciel de CAO pour créer un fichier CAO qui reflète précisément l’épaisseur du cuivre, les constantes diélectriques et les types de résine nécessaires au fonctionnement à haute fréquence. Si la carte cible est destinée à reproduire ou à modifier une conception antérieure, les nouvelles données Gerber doivent maintenir la stabilité d’impédance, la distribution thermique et l’isolation EMI.
Once the stackup is complete, the final step is generating clean, manufacturable Gerber file output. The resulting structure must reflect all key performance rules: RF stability, digital integrity, EMI suppression, thermal balance, and mechanical reliability. By following these principles—and by leveraging past designs through careful recovery, remanufacture, and duplication—engineers can create a robust multilayer PCB optimized for next-generation counter-UAV missions.
